REPLETION OF VASOPRESSIN AND OXYTOCIN IN THE POSTERIOR LOBE OF THE PITUITARY GLAND OF THE RAT

1968 ◽  
Vol 40 (3) ◽  
pp. 337-342 ◽  
Author(s):  
T. K. YOUNG ◽  
H. B. VAN DYKE
Keyword(s):  
Drinking Water ◽  
Pituitary Gland ◽  
Free Access ◽  
Posterior Lobe ◽  
Neurohypophysial Hormones ◽  
Depletion Rate ◽  
Access To Water ◽  
The Mean

SUMMARY Rats deprived of drinking water for 7 days showed a striking depletion of neurohypophysial hormones from the posterior lobe of the pituitary gland. The average daily depletion rate was estimated to be 93 m-u. for vasopressin and 97 m-u. for oxytocin. When rats were allowed free access to water, dehydration was rapidly corrected as shown by normal haematocrit values and plasma osmolarities. Repletion of neurohypophysial hormones, rapid in the first 24 hr., continued gradually thereafter. The mean calculated repletion rate was 41 m-u./day for vasopressin and 42 m-u./day for oxytocin. Repletion was completed about 14 days after rehydration.

Obestatin acts in brain to inhibit thirst

2007 ◽  
Vol 292 (1) ◽  
pp. R637-R643 ◽  
Author(s):  
Willis K. Samson ◽  
Meghan M. White ◽  
Christopher Price ◽  
Alastair V. Ferguson
Keyword(s):  
Food Intake ◽  
Pituitary Gland ◽  
Behavioral Activity ◽  
Free Access ◽  
Gene Encoding ◽  
Gh Secretion ◽  
Water Drinking ◽  
Access To Water

Derived from the same prohormone, obestatin has been reported to exert effects on food intake that oppose those of ghrelin. The obestatin receptor GPR39 is present in brain and pituitary gland. Since the gene encoding those two peptides is expressed also in those tissues, we examined further the possible actions of obestatin in vivo and in vitro. Intracerebroventricular administration of obestatin inhibited water drinking in ad libitum-fed and -watered rats, and in food-and water-deprived animals. The effects on water drinking preceded and were more pronounced than any effect on food intake, and did not appear to be the result of altered locomotor/behavioral activity. In addition, obestatin inhibited ANG II-induced water drinking in animals provided free access to water and food. Current-clamp recordings from cultured, subfornical organ neurons revealed significant effects of the peptide on membrane potential, suggesting this as a potential site of action. In pituitary cell cultures, log molar concentrations of obestatin ranging from 1.0 pM to 100 nM failed to alter basal growth hormone (GH) secretion. In addition, 100 nM obestatin failed to interfere with the stimulation of GH secretion by GH-releasing hormone or ghrelin and did not alter the inhibition by somatostatin in vitro. We conclude that obestatin does not act in pituitary gland to regulate GH secretion but may act in brain to alter thirst mechanisms. Importantly, in rats the effects of obestatin on food intake may be secondary to an action of the peptide to inhibit water drinking.

scholarly journals Changes in the renal handling of urea in sheep on a low protein diet exposed to saline drinking water

2004 ◽  
Vol 71 (3) ◽  
Author(s):  
R.A. Meintjes ◽  
H. Engelbrecht
Keyword(s):  
Drinking Water ◽  
Phase 1 ◽  
Isotonic Saline ◽  
Fractional Excretion ◽  
Protein Diet ◽  
Free Access ◽  
Urea Excretion ◽  
Low Protein ◽  
Access To Water ◽  
Urea Reabsorption

Previous trials have demonstrated that sheep on a low protein diet and free access to water, and sheep dosed with boluses of NaCl intraruminally also with free access to water, showed decreases in urea loss via the urine compared to control animals. We monitored urea excretion in sheep on a relatively poor protein diet when they were exposed to saline drinking water, i.e. they were unable to vary their intake of NaCl:water. Sheep on isotonic saline drinking water (phase 3) excreted significantly more urea via the urine (284 mM/day) compared to phase 1 when they were on non-saline drinking water (urea excretion = 230 mM/day) and phase 2 when they were on half isotonic saline drinking water (urea excretion = 244 mM/day).This finding was explained by the high glomerular filtration rate (GFR) 91.9 ℓ/day, compared to 82.4 ℓ/day (phase 1) and 77.9 ℓ/day (phase 2), together with a significantly raised fractional excretion of urea (FEurea) (51.1 %) during this phase, and was in spite of the significantly lower plasma concentrations of urea in phase 3 compared to phase 1. The FEurea probably results from the osmotic diuresis caused by the salt. There were indications of a raised plasma antidiuretic hormone (ADH) concentration and this would have opposed urea loss, as ADH promotes urea reabsorption. However, this ADH effect was probably counteracted to some extent by a low plasma angiotensin II concentration, for which again there were indications, inhibiting urea reabsorption during the phases of salt loading. As atrial natriuretic peptide both increases GFR and decrease sodium reabsorption from the tubule, it was probably instrumental in causing the increase in GFR and the increase in the fractional excretion of sodium (FENa).

scholarly journals Effects of feeding and short-term fasting on water and electrolyte turnover in female mink (Mustela vison)

1996 ◽  
Vol 76 (5) ◽  
pp. 711-725 ◽  
Author(s):  
Søren Wamberg ◽  
Anne-Helene Tauson ◽  
Jan Elnif
Keyword(s):  
Drinking Water ◽  
Daily Intake ◽  
Mustela Vison ◽  
Free Access ◽  
Urine Collection ◽  
Fasting Period ◽  
Balance Study ◽  
Percentage Recovery ◽  
Osmotic Pumps ◽  
The Mean

Daily (24 h) rates of water and electrolyte turnover were measured in a conventional balance study in ten adult female pastel mink (Mustela vison) given free access to a standard mink feed for a 1-week conditioning period, followed by a 4 d experimental period and a 2 d fasting period. Drinking water was available throughout. In addition, the completeness of urine collection and the fraction of urine collected with the faeces were determined using a new experimental technique based on 24 h recoveries of specific urinary markers such as tritiatedp-aminohippuric acid ([3H]PAH) or14C-1abelled inulin ([14C]IN) continuously delivered by small Alzet® osmotic pumps implanted intraperitoneally. During feeding the mean individual percentage recovery in urine of [3H]PAH released from tbe osmotic pumps ranged from 68 to 88% (median 78%). Tbe mean percentage of urinary [3H]PAH recovered from faecal collections was 6% (range 3–12%). In response to fasting the mean individual percentage recovery of [3H]PAH in urine ranged from 62 to 78% (median 68%). For urinary [14C]IN the mean percentage recoveries in fed and fasted animals were 79 and 63% respectively. Furthermore, during fasting, withdrawal of the supplies of dietary water caused a slight but insignificant (P = 0·17) increase in the daily intake of drinking water and, hence, the animals maintained their normal water balance by a dramatic reduction in urine excretion (P < 0·001). At the same time urinary solute excretion declined significantly (P < 0·001), due in part to the cessation of dietary electrolyte intake and in part to reduced formation of urea, whereas urinary osmolality decreased only moderately. The mean 24 h balances of Na, K, Ca, Mg, Cl and P were close to zero and only minor differences between the feeding and fasting periods were observed. When corrected for the measured inaccuracies in urine collection the balance data obtained in the present study represent useful reference standards for normally fed and fasted non-growing mink and, to some extent, useful guidelines for future studies in experimental animals.

scholarly journals Multiple Tumorous Lesions of The Pituitary Gland

2021 ◽  
Author(s):  
Jannik von Schöning ◽  
Jörg Flitsch ◽  
Dieter K Lüdecke ◽  
Rundolph Fahlbusch ◽  
Michael Buchfelder ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Pituitary Gland ◽  
Neuroendocrine Tumors ◽  
Pituitary Tumors ◽  
Posterior Lobe ◽  
Large Collection ◽  
Mesenchymal Tumors ◽  
Continuous Increase ◽  
The Mean ◽  
German Registry

Abstract Multiple tumorous lesions with an adenoma make up 1.4 % (232 cases) in the large collection of the German Registry of Pituitary Tumors. 2.0% of all PitNETs are associated with a second lesion. Within the selected cases synchronous multiple pituitary neuroendocrine tumors (PitNETs) account for 17,3%, PANCH cases for 14.7%, PitNETs and posterior lobe tumors for 2.2%, PitNETs and metastases for 5.2%, PitNETs and mesenchymal tumors for 2.6%, PitNETs and cysts for 52.2% and PitNETs and primary inflammation for 6.0%. The mean patient age was 53.8 years with a standard deviation of 18.5 years. 55.3% of the patients were female and 44.7% were male. From 1990 to 2018 there was a continuous increase in the number of multiple tumorous lesions.

THE EFFECTS OF INGESTION OF HYPERTONIC SALINE ON THE PITUITARY GLAND IN THE RAT: A MORPHOLOGICAL STUDY OF THE PARS INTERMEDIA AND POSTERIOR LOBE

1962 ◽  
Vol 25 (2) ◽  
pp. 161-NP ◽  
Author(s):  
L. W. DUCHEN
Keyword(s):  
Sodium Chloride ◽  
Pituitary Gland ◽  
Mitotic Activity ◽  
Hypertonic Saline ◽  
Morphological Study ◽  
Tap Water ◽  
Neurosecretory Material ◽  
Pars Intermedia ◽  
Posterior Lobe ◽  
Neurohypophysial Hormones

SUMMARY The microscopic changes occurring in the pars intermedia and posterior lobe of the pituitary gland were studied in rats given 2% sodium chloride in place of tap water for periods ranging from 1 to 21 days. In the pars intermedia small, strongly PAS-positive cells which are normally few in number became very numerous during the first few days of treatment with saline. After longer periods on saline these changes appeared to regress. Mitotic activity in the pars intermedia and posterior lobe was studied using colchicine. Mitoses were present in the pars intermedia of control rats but not in that of salt-loaded rats. In the posterior lobe mitoses were not present in control rats but were numerous in rats drinking saline, and the greatest numbers were seen after 4 days. The neurosecretory material (NSM) was lost from the posterior lobe within the first 8 days, and it is suggested that there is a relationship between the loss of NSM and mitotic activity in the posterior lobe. The significance of the changes in the pars intermedia is not apparent at present but may be related to the removal of neurohypophysial hormones.

scholarly journals EFFECT OF TRIDAXPROCUMBENS EXTRACTS ON BLOOD CLOTTING

2019 ◽  
pp. 8-13
Author(s):  
Atchade S. Pascal ◽  
Hoteyi Ismael ◽  
Seibou Toleba Soumanou ◽  
Bello Kaokab ◽  
Sezan Alphonse
Keyword(s):  
Platelet Count ◽  
Blood Clotting ◽  
Bleeding Time ◽  
Blood Parameters ◽  
The Body ◽  
Free Access ◽  
Phytochemical Screening ◽  
Coagulation Time ◽  
Access To Water ◽  
The Mean

Objective: The present work has focused on evaluating the effect of tridaxprocumbens on blood clotting.Methods: in the course of our study we have therefore carried out a Hydro ethanol extraction (50/50), Liquid-Solid extraction, and phytochemical screening. Thereafter our study was carried out on nine (09) male and female Wistar type rats aged from 10 to 12 w and weighing between 100 and 200 g. These animals were raised at the laboratory of Biomembranes Laboratory and Cell Signaling from FAST to UAC under standard environmental conditions. Animals have free access to water and food. 09 rats are experienced, divided in three batches of 3 rats each, submitted respectively to the following treatment: fed with distilled water, fed with 100 mg/kg P. C tridax extract procumbens, fed at 300 mg/kg P. C tridax extract procumbens. Evolution of the weight of rats during treatment was measured. After 7 d of treatment, the blood of the rats is taken for an experience of bleeding time, experience of coagulation time, and dosage of some blood parameters (platelet, partial thromboplastin, prothrombin).Results: Phytochemical screening carried out on the leaf and stem powder of Tridaxprocumbens revealed the presence of phenolic compounds, flavonoids, reducing sugar, mucilage, terpene and sterol, but at varying proportions. After 7 d of treatment, evaluation of the effect of the extractions on the body weight of the rats gave interesting conclusions. The weight of the control rats did indeed increase while that of the rats treated with the dose of (100 and 300 mg/kg) dropped. In addition, the effect of the hydroethanolic extract of the leaves and stems of Tridaxprocumbens on the coagulation of blood has been studied in order to verify the alleged property that the said extract can be used to manage bleeding. This was done by examining the effect of the extract on bleeding time, coagulation time, platelet count, activated partial thromboplastin time and prothrombin rate. These were carried out using the Duke method and the Lee and White method. In the bleeding time experiment, the mean time without adding the extract was 2.58±0.31 min, while the mean bleeding time after treatment with the extract was 1.61±0.70 min at a dose of 100 mg/kg PC and 1.77±0.69 min at a dose of 300 mg/kg PC, achieving 57% of the decrease in normal bleeding time. Thus the extract significantly lowers the bleeding time.When the extract was used for the coagulation time, it was found that the extract promotes blood clotting. In addition, this study reveals that Tridaxprocumbens significantly influences TCA, TP and platelet count at varying doses.Conclusion: The plant material studied in this study is, therefore, a credible alternative for an effective fight against bleeding and also promotes the coagulation of blood.

Milk yield of dairy cows given restricted access to water in a Mediterranean-type climate

1981 ◽  
Vol 21 (109) ◽  
pp. 167 ◽  
Author(s):  
KR King ◽  
CR Stockdale
Keyword(s):  
Drinking Water ◽  
Dairy Cows ◽  
Milk Yield ◽  
Dry Matter ◽  
The Other ◽  
Dry Matter Intake ◽  
Free Access ◽  
Restricted Access ◽  
Access To Water ◽  
Maximum Air Temperature

During summer in the Goulburn Valley, two herds of Jersey- Friesian crossbred cows were used to study the effects of restricted access to drinking water. There were three treatments applied to two herds-(1) free access, (2) 20 min. access before each milking, and (3) 20 min. access before the night milking only. One herd was individually penned and had free access to shade while the other was grazed with no access to shade. Both herds were fed irrigated perennial pasture containing 24.5% dry matter. Maximum air temperature averaged 33.7�C. Over the whole experiment, restricting the access of dairy cows to drinking water did not significantly reduce mean milk yield (mean 12.6 kg/cow day-1) or mean liveweight of cows (mean 41 1 kg) in either herd. However, during the first 4 days of treatment, mean milk yield and mean liveweight were lower (P < 0.05) for cows on a once-a-day access than for those on either free or twice-daily access. In the pen experiment, intake of drinking water averaged 67,45 and 49 l/cow day-1 for treatments 1, 2 and 3, respectively; dry matter intake was unaffected by treatment (mean 15.6 kg/cow day-1). Because of the modifying influence of shade on the environment of the penned cows, there was no significant effects of climate on their water intake. It was concluded that farmers need not supply drinking water to dairy cows in all paddocks.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

Pituitary and ovarian response to transient doe-litter separation in nursing rabbits

Reproduction ◽  
2000 ◽  
pp. 361-366 ◽  
Author(s):  
E Ubilla ◽  
PG Rebollar ◽  
D Pazo ◽  
AI Esquifino ◽  
JM Alvarino
Keyword(s):  
Pituitary Gland ◽  
Litter Size ◽  
Artificial Insemination ◽  
Ovarian Response ◽  
Major Effect ◽  
Free Access ◽  
Plasma Prolactin ◽  
Follicular Waves ◽  
Higher Sensitivity

The effects of a transient doe-litter separation on plasma prolactin, FSH and oestradiol concentrations, as well as the effect on LH response to exogenous GnRH administered at the time of artificial insemination, were determined in nursing rabbits. The effects on fertility, and litter size after parturition, as well as litter survival after doe-litter separation, were also studied. Control does (n = 12) had free access to nursing, whereas biostimulated does (n = 12) were separated from their litters for 48 h before artificial insemination. Plasma prolactin concentrations were decreased 24 h after the doe-litter separation (P < 0.05). The response of prolactin to suckling reached 10 times the basal values measured on day 10 after parturition (P < 0.0001). Increased oestradiol concentrations were found during the 48 h after the doe-litter separation: at 0 h, before artificial insemination (P< 0. 0001), 1.0-2.0 h after artificial insemination (P < 0.001), at 2.5 h (P < 0.05), 3.0 h (P < 0.01), and at 3.5 h (P < 0.05) after artificial insemination. Exogenous GnRH administered at the time of artificial insemination caused a greater LH response in does previously separated from their litters during 48 h (P < 0.01). The transient doe-litter separation did not affect plasma FSH concentrations, fertility, litter size or litter survival. These results suggest that a transient separation of nursing does from their litters before artificial insemination results in a decrease in plasma prolactin concentrations that could promote growth of follicular waves, and high steroidogenesis activity, leading to increased oestradiol concentrations and inducing higher sensitivity of the pituitary gland to exogenous GnRH. These findings associated to the absence of suckling episodes would lead to higher LH response and, therefore, exert a major effect on fertility.

Ensuring access to water in an emergency context: Towards an overexploitation and contamination of water resources?

2021 ◽  
pp. 096466392110316
Author(s):  
Chloé Nicolas-Artero
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Qualitative Methods ◽  
Water Scarcity ◽  
Water Rights ◽  
Environmental Crisis ◽  
Supply Network ◽  
Mining Pollution ◽  
Access To Water

This article shows how geo-legal devices created to deal with environmental crisis situations make access to drinking water precarious and contribute to the overexploitation and contamination of water resources. It relies on qualitative methods (interviews, observations, archive work) to identify and analyse two geo-legal devices applied in the case study of the Elqui Valley in Chile. The first device, generated by the Declaration of Water Scarcity, allows private sanitation companies to concentrate water rights and extend their supply network, thus producing an overexploitation of water resources. In the context of mining pollution, the second device is structured around the implementation of the Rural Drinking Water Programme and the distribution of water by tankers, which has made access to drinking water more precarious for the population and does nothing to prevent pollution.

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