Excretion of corticosteroid metabolites in urine and faeces of rats

2001 ◽  
Vol 35 (4) ◽  
pp. 307-314 ◽  
Author(s):  
E. Bamberg ◽  
R. Palme ◽  
J. G. Meingassner

Stress enhances the production of corticosteroids by the adrenal cortex, resulting in the increased excretion of their metabolites in urine and faeces. An intraperitoneal injection of radioactive corticosterone was applied to adult, male Sprague-Dawley rats to monitor the route and delay of excreted metabolites in urine and faeces. Peak concentrations appeared in urine after 3.2 ± 1.9 h and in faeces after 16.7 ± 4.3 h. Altogether about 20% of the recovered metabolites were found in urine and about 80% in faeces. Using high-performance liquid chromatography (HPLC), several peaks of radioactive metabolites were found. Some metabolites were detected by enzyme immunoassay (EIA) using two different antibodies (corticosterone, 11β-OH-aetiocholanolone). There was a marked diurnal variation with low levels of faecal corticosterone metabolites in the evening and higher values in the morning. This diurnal variation was influenced neither by the intraperitoneal injection of isotonic saline nor by ACTH. However, the administration of dexamethasone eliminated the morning peak for 2 days.

2003 ◽  
Vol 73 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Romans ◽  
Barua ◽  
Olson

The purpose of this study was to examine the pharmacokinetics of a single dose (6.3 mumol, 3 mg) of all-trans retinoyl beta-glucuronide (RAG), when given either orally in corn oil or by intraperitoneal (IP) injection in dimethylsulfoxide (DMSO) to adult Sprague-Dawley rats. Following dosing, serial blood samples were collected at various times up to 48 hours from each rat via saphenous vein puncture. Retinoids were extracted from plasma samples and analyzed by high-performance liquid chromatography. In the plasma of IP-dosed rats (n = 6), a derivative of RAG, tentatively identified as the lactone of RAG (RAGL), was the major product found. RAGL persisted in the plasma for up to 48 hours. Much smaller concentrations of RAG and of retinoic acid (RA) were also present in the plasma at two to four hours, but generally not thereafter. In orally dosed rats (n = 6), neither RAG nor its products, except for occasional traces of the lactone, were detected. Plasma retinol levels decreased in both IP-injected and orally treated rats, the decrease being significant in orally dosed rats.


Amino Acids ◽  
2021 ◽  
Author(s):  
Tomohisa Yoshimura ◽  
Yuki Inokuchi ◽  
Chikako Mutou ◽  
Takanobu Sakurai ◽  
Tohru Nagahama ◽  
...  

AbstractTaurine, a sulfur-containing amino acid, occurs at high concentrations in the skin, and plays a role in maintaining the homeostasis of the skin. We investigated the effects of aging on the content and localization of taurine in the skin of mice and rats. Taurine was extracted from the skin samples of hairless mice and Sprague Dawley rats, and the taurine content of the skin was determined by high-performance liquid chromatography (HPLC). The results of the investigation revealed that the taurine content in both the dermis and epidermis of hairless mice declined significantly with age. Similar age-related decline in the skin taurine content was also observed in rats. In contrast, the taurine content in the sole remained unchanged with age. An immunohistochemical analysis also revealed a decreased skin taurine content in aged animals compared with younger animals, although no significant differences in the localization of taurine were observed between the two age groups. Supplementation of the drinking water of aged mice with 3% (w/v) taurine for 4 weeks increased the taurine content of the epidermis, but not the dermis. The present study showed for the first time that the taurine content of the skin decreased with age in mice and rats, which may be related to the impairment of the skin homeostasis observed with aging. The decreased taurine content of the epidermis in aged animals was able to be rescued by taurine supplementation.


2009 ◽  
Vol 29 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Amal A El-Bakary ◽  
Sahar A El-Dakrory ◽  
Sohayla M Attalla ◽  
Nawal A Hasanein ◽  
Hala A Malek

Methanol poisoning is a hazardous intoxication characterized by visual impairment and formic acidemia. The therapy for methanol poisoning is alcohol dehydrogenase (ADH) inhibitors to prevent formate accumulation. Ranitidine has been considered to be an inhibitor of both gastric alcohol and hepatic aldehyde dehydrogenase enzymes. This study aimed at testing ranitidine as an antidote for methanol acute toxicity and comparing it with ethanol and 4-methyl pyrazole (4-MP). This study was conducted on 48 Sprague-Dawley rats, divided into 6 groups, with 8 rats in each group (one negative control group [C1], two positive control groups [C2, C3] and three test groups [1, 2 and 3]). C2, C3 and all test groups were exposed to nitrous oxide by inhalation, then, C3 group was given methanol (3 g/kg orally). The three test groups 1, 2 and 3 were given ethanol (0.5 g/kg orally), 4-MP (15 mg/kg intraperitoneally) and ranitidine (30 mg/kg intraperitoneally), respectively, 4 hours after giving methanol. Rats were sacrificed and heparinized, cardiac blood samples were collected for blood pH and bicarbonate. Non-heparinized blood samples were collected for formate levels by high performance liquid chromatography. Eye balls were enucleated for histological examination of the retina. Ranitidine corrected metabolic acidosis (p = .025), decreased formate levels (p = .014) and improved the histological findings in the retina induced by acute methanol toxicity.


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