The pineal gland and aldosterone

1960 ◽  
Vol 199 (6) ◽  
pp. 1109-1111 ◽  
Author(s):  
Richard Jay Wurtman ◽  
Mark D. Altschule ◽  
Roy O. Greep ◽  
John L. Falk ◽  
Gilman Grave

It has recently been suggested that the canine pineal gland secretes a hormone which stimulates the adrenal cortex to release aldosterone. The following experiments were undertaken to determine what effect pinealectomy or administration of bovine pineal extracts has on certain physiologic variables associated with aldosterone activity in rats: a) the relative size of the zona glomerulosa, compared with total adrenal area, was determined planimetrically in 25 female rats treated with pinealectomy, pineal extracts, or both; b) urinary potassium excretion was measured in 4 pinealectomized and 4 control female rats; c) the elective saline intakes, at concentrations ranging from 0 to 3.0%, were measured in 5 male control rats and in 5 animals given 1.0 ml/day of pineal extract. Pinealectomy or pineal extract had no effect on any of these variables, suggesting that the pineal gland does not regulate aldosterone secretion in the rat.

1968 ◽  
Vol 57 (4) ◽  
pp. 585-594 ◽  
Author(s):  
N. Prop ◽  
I. Ebels

ABSTRACT Injections of a water-soluble pineal extract into young female rats kept under a normal light/dark rhythm caused a relatively high frequency of abnormal nuclei in the pineal gland. This nuclear response suggests a secretory activity in normal pinealocytes. No effect of the pineal extract on the reproductive system was observed. In females exposed to continuous light, neither the water-soluble extract nor the acetone-soluble pineal material interfered with the light induced alterations in the oestrous cycle, the uterine and ovarian weights, the condition of the pineal nuclei and the quantity of pineal lipids.


1961 ◽  
Vol 36 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Richard Jay Wurtman ◽  
Willard Roth ◽  
Mark D. Altschule ◽  
Judith J. Wurtman

ABSTRACT Either exposure to constant light for 80 days or pinealectomy produced similar changes in the weights of the ovaries and adrenals of female rats. These were not additive when both procedures were employed. Pinealectomy did not share with light-exposure the capacity to induce uterine hypertrophy. Rats exposed to constant light for 56 days had lighter pineals than animals kept in darkness; this decrease was not affected by administration of bovine pineal extracts. The increase in ovarian weight produced in rats by exposure to light for 56 days was prevented by bovine pineal extracts, but these extracts were without effect on the uterine hypertrophy produced under the same conditions. These data suggest that the effect of light upon the weight of the ovary is mediated via the pineal.


1977 ◽  
Vol 85 (2) ◽  
pp. 225-234 ◽  
Author(s):  
R. J. Orts ◽  
K. M. Kocan ◽  
R. P. Johnson

ABSTRACT Bovine pineal glands were extracted with acetic acid and partially purified on Sephadex G-25. Three fractions, F3, F4 and F5, were each administered to cycling female rats for 4, 2 or 1 day prior to ovulation to determine their effects on fertility, ovulation and the pro-oestrous surge of luteinizing hormone (LH). The incidence of pregnancy and the mean number of foetuses were reduced in animals after treatment with F3 or F4 but not in those treated with F5. Each of the F3 and F4 fractions significantly reduced the mean number of ova shed and the pre-ovulatory concentration of serum LH. The F5 fraction caused a moderate reduction of the pro-oestrous rise of serum LH but had no significant effect on ovulation. The data suggest that fertility in rats can be reduced by more than one substance of low molecular weight present in bovine pineal extracts through a modifying effect on LH secretion and subsequent ovulation.


2021 ◽  
Vol 4 (1) ◽  
pp. 99-114
Author(s):  
Janaína B Garcia ◽  
Fernanda G Do Amaral ◽  
Daniela C Buonfiglio ◽  
Rafaela FA Vendrame ◽  
Patrícia L Alves ◽  
...  

The pineal gland synthesizes melatonin exclusively at night, which gives melatonin the characteristic of a temporal synchronizer of the physiological systems. Melatonin is a regulator of insulin activities centrally and also peripherally and its synthesis is reduced in diabetes.  Since monosodium glutamate (MSG) is often used to induce the type 2 diabetic and metabolic syndrome in animal models, the purpose of this work is to evaluate the potential effects of MSG given to neonates on the pineal melatonin synthesis in different aged male and female rats. Wistar rats were subcutaneously injected with MSG (4mg/g/day) or saline solution (0.9%) from the second to eighth post-natal day. The circadian profiles both melatonin levels and AANAT activity were monitored at different ages. Body weight, naso-anal length, adipose tissues weight, GTT, ITT and serum insulin levels were also evaluated. Typical obesity with the neonatal MSG treatment was observed, indicated by a great increase in adipose depots without a concurrent increase in body weight. MSG treatment did not cause hyperglycemia or glucose intolerance, but induced insulin resistance. An increase of melatonin synthesis at ZT 15 with phase advance was observed in in some animals. The AANAT activity was positively parallel to the melatonin circadian profile. It seems that MSG causes hypothalamic obesity which may increase AANAT activity and melatonin production in pineal gland. These effects were not temporally correlated with insulin resistance and hyperinsulinemia indicating the hypothalamic lesions, particularly in arcuate nucleus induced by MSG in early age, as the principal cause of the increase in melatonin production.


1970 ◽  
Vol 63 (4) ◽  
pp. 667-678 ◽  
Author(s):  
Russel J. Reiter

ABSTRACT The influence of early androgen treatment, light deprivation (by blinding), pinealectomy and superior cervical ganglionectomy on the reproductive system of female rats was tested. Early postnatal treatment of rats with testosterone propionate caused adult rats to exhibit the characteristic signs of androgen sterilization; these included polyfollicular ovaries, normal-sized uteri and persistent vaginal cornification. If early androgentreated rats also were blinded the ovaries were smaller in size and contained fewer follicles, the uteri were greatly reduced in size and the incidence of vaginal oestrus was decreased by approximately 50% If in addition to blinding, androgen-sterilized animals were subjected to either removal of the pineal gland or superior cervical ganglia, the reproductive organs and the vaginal smears were indistinguishable from those of testosterone-treated rats with eyes. These data indicate that the inhibitory influence of blinding on the pituitary-ovarian axis was mediated through the sympathetic nervous system and the pineal gland. The restraining influence of light deprivation on the growth of the reproductive organs was not permanent as illustrated by the fact that if these animals were kept to 120 days of age the ovaries and uteri grew to the same level as those of pinealectomized control rats.


1995 ◽  
Vol 305 (2) ◽  
pp. 433-438 ◽  
Author(s):  
S Kapas ◽  
A Purbrick ◽  
J P Hinson

The role of protein kinases in the steroidogenic actions of alpha-melanocyte-stimulating hormone (alpha-MSH), angiotensin II (AngII) and corticotropin (ACTH) in the rat adrenal zona glomerulosa was examined. Ro31-8220, a potent selective inhibitor of protein kinase C (PKC), inhibited both AngII- and alpha-MSH-stimulated aldosterone secretion but had no effect on aldosterone secretion in response to ACTH. The effect of Ro31-8220 on PKC activity was measured in subcellular fractions. Basal PKC activity was higher in cytosol than in membrane or nuclear fractions. Incubation of the zona glomerulosa with either alpha-MSH or AngII resulted in significant increases in PKC activity in the nuclear and cytosolic fractions and decreases in the membrane fraction. These effects were all inhibited by Ro31-8220. ACTH caused a significant increase in nuclear PKC activity only, and this was inhibited by Ro31-8220 without any significant effect on the steroidogenic response to ACTH, suggesting that PKC translocation in response to ACTH may be involved in another aspect of adrenal cellular function. Tyrosine phosphorylation has not previously been considered to be an important component of the response of adrenocortical cells to peptide hormones. Both AngII and alpha-MSH were found to activate tyrosine kinase, but ACTH had no effect, observations that have not been previously reported. Tyrphostin 23, a specific antagonist of tyrosine kinases, inhibited aldosterone secretion in response to AngII and alpha-MSH, but not ACTH. These data confirm the importance of PKC in the adrenocortical response to AngII and alpha-MSH, and, furthermore, indicate that tyrosine kinase may play a critical role in the steroidogenic actions of AngII and alpha-MSH in the rat adrenal zona glomerulosa.


2015 ◽  
Vol 3 (1) ◽  
pp. 5 ◽  
Author(s):  
Barnabé Lucien Nkono Ya Nkono ◽  
Selestin Dongmo Sokeng ◽  
Paul Désiré Dzeufiet Djomeni ◽  
Frida Longo ◽  
Pierre Kamtchouing

<p><strong>Methodology:</strong> Wistar rats were randomly assigned into eight groups of five animals each: four male groups and four female groups. Each sex group had a control group receiving distilled water and three test groups receiving 200, 500 and 1000mg/kg respectively. Animal’s body weights were recorded on the first day and once a week for the four experiment weeks. The hematological analysis included total WBC count, total RBC count, Hb, %HCT, MCV, MCH and MCHC. Biochemical/serum profile studies include TG, TC, ALT, AST, urea and TP. Tissue specimens of the liver, kidney and lung were subjected to histological examination using standard hematoxylin-eosin staining.</p><p><strong>Results:</strong> In male rats, aqueous extract showed significant decreases in relative weight of liver with extreme significance P&lt;0.001 at a dose of 200mg/kg (vs. control group), P&lt;0.001 of lung at all the doses, P&lt;0.05 (200 and 500mg/kg) and P&lt;0.01 (1000mg/kg) in heart weight. In relative kidney weight, only the dose of 1000mg/kg showed a significant increase vs. normal control male rats. Unlike male rats, only relative kidney weight in female rats was significantly different from the control group in a dose-dependent manner. The aqueous extract treated male groups showed significant increases P&lt;0.001 (1000mg/kg) of total WBC count and MCHC, significant decreases of %HTC (dose response manner), P&lt;0.05 total RBC count (at doses of 500 and 1000mg/kg) and Hb P&lt;0.01 (500mg/kg) vs. normal male rats. In female rats, the haematological study showed significant increase P&lt;0.01 of total WBC count (at the doses of 500 and 1000mg/kg), significant decreases P&lt;0.05 and P&lt;0.01 of total RBC respectively at the doses of 200 and 1000mg/kg, significant decrease of Hb with extreme significance P&lt;0.001 at the dose 1000mg/kg, %HTC also decrease dose response manner vs. control female rats. Biochemical study showed in male rats significant decreases in level of TG P&lt;0.001 (at the doses of 200 and 500mg/kg) and urea, although it showed any dose-dependent effect vs. control male rats. AST also decreases (P&lt;0.05) in male rats at the dose of 200mg/kg but significantly increase P&lt;0.001 at the dose of 500mg/kg. In the female rats, biochemical study revealed significant increases in level of TG P&lt;0.001 and urea P&lt;0.01 at the dose of 200mg/kg and significant decreases in level of TG P&lt;0.01, AST P&lt;0.05 and urea P&lt;0.05 at the dose of 500mg/kg (vs. control female rats). Microscopically, there were mild hepatic and renal tissue injuries supporting the hematological analysis.</p><p><strong>Conclusion:</strong> The results indicated that aqueous extract of <em>Alstonia boonei</em> De Wild is toxic in high doses.</p>


Author(s):  
Jinbo Hu ◽  
Hang Shen ◽  
Peiqi Huo ◽  
Jun Yang ◽  
Peter J Fuller ◽  
...  

Background While both renin‐dependent and renin‐independent aldosterone secretion contribute to aldosteronism, their relative associations with cardiovascular disease (CVD) risk has not been investigated. Methods and Results A total of 2909 participants from the FOS (Framingham Offspring Study) with baseline, serum aldosterone concentration, and plasma renin concentration who attended the sixth examination cycle and were followed up until 2014 and who were free of CVD were included. We further recruited 2612 hypertensive participants from the CONPASS (Chongqing Primary Aldosteronism Study). Captopril challenge test was performed to confirm renin‐dependent or ‐independent aldosteronism in CONPASS. Among 1433 hypertensive subjects of FOS, when compared with those with serum aldosterone concentration <10 ng dL −1 (normal aldosterone), participants who had serum aldosterone concentration ≥10 ng dL −1 and plasma renin concentration ≤15 mIU L −1 (identified as renin‐independent aldosteronism) showed a higher risk of CVD (hazard ratio, 1.40 [95% CI, 1.08–1.82]), while those who had serum aldosterone concentration ≥10 ng dL −1 and plasma renin concentration >15 mIU L −1 (identified as renin‐dependent aldosteronism) showed an unchanged CVD risk. In CONPASS, renin‐independent aldosteronism carried a significantly higher risk of CVD than normal aldosterone (odds ratio, 2.57 [95% CI, 1.13–5.86]), while the CVD risk remained unchanged in renin‐dependent aldosteronism. Elevation of the urinary potassium‐to‐sodium excretion ratio, reflective of mineralocorticoid receptor activity, was only observed in participants with renin‐independent aldosteronism. Conclusions Among patients with hypertension, renin‐independent aldosteronism is more closely associated with CVD risk than renin‐dependent aldosteronism.


1975 ◽  
Vol 80 (1) ◽  
pp. 114-125 ◽  
Author(s):  
Katalin Sz. Szalay ◽  
Ernö Bácsy ◽  
Ervin Stark

ABSTRACT Potassium and sodium contents in the various adrenal zones were determined in experimental hyper- and hypoaldosteronism in the rat by electron probe X-ray microanalysis. The analysis aimed at revealing intracellular values. There was no change in the potassium content of the zona glomerulosa, zona fasciculata and medulla neither in hyperaldosteronism, induced by Na-deficiency, nor in hypoaldosteronism, elicited by Na-rich diet. The sodium content in the zona glomerulosa and zona fascicularis was increased in the Na-loaded rats, while that of the medulla was not changed. Our data are not consistent with the hypothesis that a change of adrenal intracellular potassium would act as a final stimulus in the regulation of aldosterone secretion.


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