scholarly journals Seasonal variations of gonadotropins and prolactin in the laboratory rat. role of maternal pineal gland

2007 ◽  
pp. 79-88
Author(s):  
N Vázquez ◽  
E Díaz ◽  
C Fernández ◽  
V Jiménez ◽  
A Esquifino ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Postnatal Development ◽  
Seasonal Variations ◽  
Wistar Rats ◽  
Reproductive Hormones ◽  
Seasonal Fluctuations ◽  
Melatonin Treatment ◽  
Laboratory Rat ◽  
Age Dependent

The laboratory rat, a non-photoperiodic rodent, exhibits seasonal fluctuations of melatonin. Melatonin has been found to be readily transferred from the maternal to the fetal circulation. No data exist on the possible influence of maternal pineal gland upon seasonal variations of the offspring. The aim of the present study was to asses the influence of the maternal melatonin rhythm on the offspring postnatal development of the reproductive hormones LH, FSH and prolactin. Male offspring from control, pinealectomized (PIN-X) and PIN-X + melatonin (PIN-X+MEL) mother Wistar rats were studied at 21, 31, and 60 days of age. Seasonal age-dependent variations were found for all hormones studied in control offspring but PIN-X offspring showed a tendency to have reduced duration or altered seasonal variations. Maternal melatonin treatment to PIN-X mothers partially restored the effect of pinealectomy. The chronological study of LH, FSH, and prolactin in PIN-X offspring also showed an altered pattern as compared to control-offspring. Melatonin treatment to the mothers partially restored the developmental pattern of reproductive hormones. Results of this study indicate that maternal pineal gland of the laboratory rat is involved in the seasonal postnatal development variations of reproductive hormones of the offspring.

Age-dependent biliary excretion of glutathione-related thiols in rats: role of gamma-glutamyltransferase

1987 ◽  
Vol 253 (1) ◽  
pp. G86-G92 ◽  
Author(s):  
Z. Gregus ◽  
A. F. Stein ◽  
C. D. Klaassen
Keyword(s):  
Postnatal Development ◽  
Biliary Excretion ◽  
Excretion Rate ◽  
Dependent Manner ◽  
Gamma Glutamyltransferase ◽  
Hydrolysis Products ◽  
Age Dependent ◽  
Old Rats ◽  
Hydrolysis Of

The role of gamma-glutamyltransferase (GGT) in the biliary excretion of glutathione (GS) was studied in rats during postnatal development. Between 2 and 10 wk of age the biliary excretion of GS-related sulfur increased ninefold. During this period, alterations were observed in both hepatic GGT and the composition of GS-related thiols and disulfides in bile. For instance, between 3 and 4 wk of age, GGT activity and the biliary excretion of GS hydrolysis products (Cys-Gly and Cys) increased markedly, and the latter became the predominant sulfhydryls in bile. However, by 10 wk of age, the excretion rate of GS increased and exceeded the rate of excretion of Cys-Gly and Cys. The parallelism between hepatic GGT activity and the biliary excretion of GS-hydrolysis products during development suggests a role for GGT in the formation of biliary Cys-Gly and Cys. Furthermore, in 4-wk-old rats, inhibition of hepatic GGT by acivicin markedly decreased the biliary excretion of Cys-Gly and Cys and increased that of GS without influencing the excretion of total GS-related sulfur in bile. The biliary excretion of GS-related thiols was less responsive to acivicin in 2- and 7- to 10-wk-old rats, suggesting that GGT plays a smaller role in influencing biliary thiol composition at those ages. In summary, GS transported into bile is hydrolyzed in an age-dependent manner, however, the GGT-initiated hydrolysis of GS does not affect the biliary excretion of total thiols in rats.

ROLE OF THE ADRENALS ON SEASONAL VARIATIONS IN SENSITIVITY RESPONSE OF THE RAT DORSOLATERAL PROSTATE TO SEX HORMONES

1959 ◽  
Vol XXXII (I) ◽  
pp. 54-58 ◽  
Author(s):  
Samuel A. Gunn ◽  
helma Clark Gould
Keyword(s):  
Sex Hormones ◽  
Reproductive Cycle ◽  
Seasonal Variations ◽  
Zn Uptake ◽  
Laboratory Rat ◽  
Discernible Effect ◽  
Seasonal Regulation

ABSTRACT It has been demonstrated previously that the seasonal variations in 65Zn uptake by the DLP represented an archaic reproductive cycle inherent in the male laboratory rat. It was also noted that the degree of sensitivity response of the DLP of the castrate to sex hormones varied seasonally coincident with this archaic cycle. The experiments reported in this paper have shown that the adrenals have three different effects in the seasonal regulation of this sensitivity response, namely, an augmenting role, a suppressing role, or no discernible effect, depending upon the phase of the archaic reproductive cycle.

Seasonal variations in HIOMT activity during the night in the pineal gland of 21 day old male wistar rats

1980 ◽  
Vol 49 (1-2) ◽  
pp. 107-116 ◽  
Author(s):  
M. G. M. Balemans ◽  
F. A. M. Bary ◽  
W. C. Legerstee ◽  
J. Van Benthem
Keyword(s):  
Pineal Gland ◽  
Seasonal Variations ◽  
Wistar Rats ◽  
Male Wistar Rats

Role of cytokines in anti-implantation activity of H2receptor blockers in albino wistar rats

2009 ◽  
Vol 00 (00) ◽  
pp. 090930024626018-7
Author(s):  
Shyam S. Agrawal ◽  
Sibi P. Ittiyavirah
Keyword(s):  
Wistar Rats

scholarly journals Circadian regulation and molecular role of the Bsx homeobox gene in the adult pineal gland

2019 ◽  
Vol 68 (2) ◽  
Author(s):  
Mikkel B. Carstensen ◽  
Henrik Hertz ◽  
Tenna Bering ◽  
Morten Møller ◽  
Kristian Rohde ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Homeobox Gene ◽  
Circadian Regulation

scholarly journals The fertility assessment of normal cyclic Wistar rats following the administration of methanolic extract of Portulaca oleracea: an experimental study

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Izuchukwu Azuka Okafor ◽  
Uchenna Somtochukwu Nnamah ◽  
Jude Nnaka
Keyword(s):  
Estrous Cycle ◽  
Adult Female ◽  
Wistar Rats ◽  
Major Effect ◽  
Reproductive Hormones ◽  
Portulaca Oleracea ◽  
High Dose ◽  
Methanolic Extracts ◽  
Cycle Arrest ◽  
Female Wistar Rats

Abstract Background Purslane is a widely distributed shrub used for the treatment of different ailments. The increasing reproductive complications associated with herbal treatments have led to the need to critically evaluate the safety and/or reproductive potentials of commonly used plant extracts. This study investigated the reproductive effect of methanolic extracts of Portulaca oleracea (MEPO) in adult female Wistar rats. Results Group C showed a significant decrease both in relative ovarian weight (p = 0.000), and relative uterine weight (p = 0.037), when compared with the control. There were no significant (p ˃ 0.05) changes in the levels of follicle-stimulating hormone, luteinizing hormone, progesterone, and estradiol. When compared to the control, groups B and C showed abnormal estrous cycle and cycle arrest especially at the metestrus phase with mild congestion of a few blood vessels in the ovary and uterus. Conclusions MEPO may possess some anti-fertility effect, as it disrupts the estrous cycle of adult female Wistar rats; although it has no major effect on the reproductive hormones, uterus, and ovarian histology of adult female Wistar rats. However, high dose consumption should be taken with precaution.

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