Diuresis in Mosquitoes: Role of a Natriuretic Factor

Physiology ◽  
1987 ◽  
Vol 2 (5) ◽  
pp. 171-175 ◽  
Author(s):  
KW Beyenbach ◽  
DH Petzel

When a mosquito takes in a blood meal that is twice its body weight, flying and easy maneuvering become a problem. To get rid of the extra water, the mosquito produces a copious flow of urine that begins even before the meal has been completed. How is this diuresis controlled?

2006 ◽  
Vol 76 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Yukari Egashira ◽  
Shin Nagaki ◽  
Hiroo Sanada

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.


2019 ◽  
Vol 17 (1) ◽  

Background: Commercial broiler is a rapidly growing sector in Bangladesh. The broilers are supplied with the balanced ration prepared from a number of ingredients which are not available uniformly throughout the years. On the other hands, manufactured feeds are costly and inconvenient for the rural farmers. This study is undertaken to use unconventional feed ingredients aiming to decrease the broiler production cost. Method: A total of ninety-nine day- old broiler chicks (Hubbard) of either sex were used in this study in 3 treatment groups to assess processed unconventional feed item (shoti, blood meal, poultry dropping and molasses) on growth and profitability upon rearing for 60 days. Broilers were reared in dip litter system and were fed ad libitum on conventional and unconventional diet dividing into 3 treatment diets namely, treatment diet 1 (T1: Conventional as control), treatment diet 2 (T2: unconventional with blood meal and shoti), and treatment diet 3 (T3: unconventional with blood meal, shoti, poultry droppings and molasses) throughout the trial period. Treatment group 1 (T1) was used as control. Results: Broilers fed on control diet (conventional feed) achieved higher (P<0.01) body weight, while the broilers offered diets with the highest amount of unconventional feed had the lowest body weight. Increased (P<0.01) feed intake was observed during 21days and 49 days of age when broilers fed diets with the supplementation, but no significant differences were found among the groups in terms of feed consumption during 33 day of age. FCR differed significantly (P<.01) throughout the trial period with the broilers fed diets without supplementation of unconventional feed item had the superior FCR than the others. Mortality rate was 6.06%,9.09%, and 9.09% in treatment group I, treatment group II, and treatment group III respectively while live weights, feed conversion and feed consumption was unaffected by all the dietary groups with/without incorporation of unconventional feed item up to day 60 days of age. Statistically significant (P<0.01) decreased live weight was observed among the treatment groups in 60-day-old birds. Productivity and cost-benefit analysis were performed. Conclusion: Use of unconventional feed ingredients in broiler production greatly reduces the feed cost with little hampering the growth rate and hence, it is profitable for the farmers.


2019 ◽  
Vol 25 (37) ◽  
pp. 4837-4853 ◽  
Author(s):  
Agata Jarząb ◽  
Wirginia Kukula-Koch

Background: Obesity in the 21st century society became an important health problem, alarming both the scientists and medicine doctors around the world. That is why, the search for new drug candidates capable to reduce the body weight is of high concern. Objective: This contribution tends to collect current findings on the biochemistry of obesity and on the application of plants and in particular turmeric tuber – a commonly used spice - as an anti-obesity agent. Methods: Following an introduction on the biochemical characteristics of obesity, the description of Curcuma secondary metabolites, their pharmacological applications and a study on the plants’ regulatory properties in obesity was summarized. Particular attention was paid to curcumin – the major metabolite present in the extracts of Curcuma spp., which is known to exhibit a variety of pharmacological actions. Also, the characteristics of some semisynthetic analogues of this ferulic acid derivative, characterized by a higher polarity and better bioavailability will be discussed. Results: Numerous scientific papers treat on the influence of turmeric on weight loss. Additionally, some of them describe its anti-inflammatory properties. Conclusions: This important spice tends to fight the 21st century plague, which is an excessive weight gain, related to the development of metabolic syndrome, to the occurrence of cardiovascular problems and diabetes, and, in consequence, leading to a significant shortening of life span. As herein proven, the extracts of turmeric play an important role in the regulation of inflammatory reactions which are evoked in the overweight patients, helping them reduce the excess body weight.


Author(s):  
Basiru Olaitan Ajiboye ◽  
Babatunji Emmanuel Oyinloye ◽  
Jennifer Chidera Awurum ◽  
Sunday Amos Onikanni ◽  
Adedotun Adefolalu ◽  
...  

Abstract Objectives The current study evaluates the protective role of aqueous extract of Sterculia tragacantha leaf (AESTL) on pancreatic gene expressions (insulin, PCNA, PDX-1, KI-67 and GLP-1R) and oxidative stress parameters in streptozotocin-induced diabetic rats. Methods Diabetes mellitus was induced into the experimental Wistar animals via intraperitoneal (IP) injection of streptozotocin (35 mg/kg body weight) and 5% glucose water was given to the rats for 24 h after induction. The animals were categorized into five groups of 10 rats each as follows normal control, diabetic control, diabetic rats administered AESTL (150 and 300 mg/kg body weight) and diabetic rats administered metformin (200 mg/kg) orally for two weeks. Thereafter, the animals were euthanized, blood sample collected, pancreas harvested and some pancreatic gene expressions (such as insulin, PCNA, PDX-1, KI-67, and GLP-1R)s as well as oxidative stress parameters were analyzed. Results The results revealed that AESTL significantly (p<0.05) reduced fasting blood glucose level, food and water intake, and lipid peroxidation in diabetic rats. Diabetic rats administered different doses of AESTL showed a substantial upsurge in body weight, antioxidant enzyme activities, and pancreatic gene expressions (insulin, PCNA, PDX-1, KI-67, and GLP-1R). Conclusions It can therefore be concluded that AESTL has the ability to protect the pancreas during diabetes mellitus conditions.


1994 ◽  
Vol 267 (2) ◽  
pp. H751-H756 ◽  
Author(s):  
A. W. Cowley ◽  
E. Szczepanska-Sadowska ◽  
K. Stepniakowski ◽  
D. Mattson

Despite the well-recognized vasoconstrictor and fluid-retaining actions of vasopressin, prolonged administration of arginine vasopressin (AVP) to normal animals or humans fails to produce sustained hypertension. The present study was performed to elucidate the role of the V1 receptor in determining the ability of AVP to produce sustained hypertension. Conscious Sprague-Dawley rats with implanted catheters were infused with the selective V1 agonist, [Phe2,Ile3,Orn8]vasopressin (2 ng.kg-1.min-1), for 14 days in amounts that were acutely nonpressor. Blood pressure (MAP), heart rate (HR), body weight, and water intake (WI) were determined daily. Plasma AVP, plasma catecholamines norepinephrine and epinephrine, plasma osmolality, and electrolyte concentration were determined before and on days 1 and 7 of infusion. MAP increased significantly by 10.4 +/- 4.5 mmHg on day 1 and rose to 22 +/- 5 mmHg above control by day 14 (transient decrease on days 6-9) and then fell to control levels after the infusion was stopped. HR did not change significantly. Plasma AVP immunoreactivity increased from 2.5 +/- 0.3 to 10.9 +/- 2.1 pg/ml, whereas norepinephrine tended to fall only on day 1, with epinephrine only slightly elevated on day 7. No evidence of fluid retention was found, and rats lost sodium only on the first day of V1 agonist infusion. Body weight increased throughout the study but was unrelated to the changes of MAP. We conclude that chronic stimulation of V1 receptors results in sustained hypertension in rats.


1985 ◽  
Vol 107 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
Y. Chabi

ABSTRACT In mink, termination of the delayed implantation period, following reactivation of the corpora lutea, and onset of the spring moult are associated with a rise in prolactin secretion triggered by increasing daylength, while decreasing daylength induces the autumn moult. To establish whether suppression of the function of the pineal rendered the mink unresponsive to daylength changes, the superior cervical ganglion was removed bilaterally 2–4 weeks before mating. Intact and operated females were then left outdoors or were put under a lighting regime of either 15 h light: 9 h darkness (15L: 9D) or 8L: 16D. In July, at the end of the spring moult, the 15L: 9D lighting regime was changed to one of 8L: 16D. Under artificial photoperiods ganglionectomy suppressed the stimulatory role of long days and the inhibitory role of short days on prolactin secretion, and consequently on progesterone secretion and spring moult. Neither was the autumn moult, induced early in intact females by the change to a short photoperiod, advanced in ganglionectomized females, showing that the latter were unresponsive to the artificial modification of the photoperiod. However, in animals kept outdoors, prolactin and progesterone secretion and spring moult were not changed by ganglionectomy. Increase in body weight and autumn moult were only slightly delayed by the operation suggesting that other environmental factors had replaced the synchronizing effect of the daylength changes. Alternatively the desynchronization between intact females responsive to photoperiodism and those rendered unresponsive may be too slow to be observed soon after ganglionectomy. J. Endocr. (1985) 107, 31–39


2009 ◽  
Vol 3 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Tsuneo Ogawa ◽  
Monica Forero ◽  
Patrick G. Burgon ◽  
Mercedes L. Kuroski de Bold ◽  
Tina Georgalis ◽  
...  

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