Steroid biosynthesis

About: Steroid biosynthesis is a research topic. Over the lifetime, 1721 publications have been published within this topic receiving 58977 citations.

New approaches in human adrenocortical pathology: Assessment of adrenocortical function in surgical specimen of human adrenal glands.

Abstract: In adrenocortical pathology, it is important to localize the sites of steroid biosynthesis in order to obtain a better understanding of steroid metabolism. Previous morphological techniques, including light- and electron-microscopical examination, histochemistry, and immunohisto-chemistry of steroids, as well as biochemical studies, could not satisfactorily demonstrate which types of cortical cells produce which steroid hormones. Recent purification and characterization of specific steroidogenic enzymes, such as cytochrome P-450, that are involved in adrenal steroid biosynthesis have made it possible to generate specific antibodies and DNA probes against the enzymes that catalyze specific reaction(s) in the complicated biochemical cascade of steroidogenesis. By employing these antibodies and DNA probes, it has became possible to detect the expression of specific steroidogenic enzymes in surgically resected human adrenal cortex and its disorders. This can indicate the site(s) of specific steroid hormone(s) catalyzed by the expressed enzymes.

Crocin-I ameliorates the disruption of lipid metabolism and dysbiosis of the gut microbiota induced by chronic corticosterone in mice.

Abstract: Glucocorticoids (GCs) are widely used as anti-inflammatory and immunosuppressive drugs. However, chronic treatment with GCs in clinical settings has a series of side effects, such as metabolic disorders, gut microbiota dysbiosis and neurological impairment. Therefore, searching for a functional substance that can alleviate these side effects is greatly meaningful to clinical patients. Crocin is the main active ingredient of saffron, which has been reported to have numerous pharmacological activities. However, the action of crocin-I, one major member of the crocin family, on the physiological mediation in the individuals receiving GC treatment remains unclear. In this study, we aimed to evaluate the efficacy of crocin-I on lipid metabolism and the gut microbiota in a mouse model of chronic corticosterone (CORT) treatment. Our findings showed that crocin-I reduced the levels of triglycerides and total cholesterol and the ratio of low density lipoprotein to high density lipoprotein in the serum of CORT-treated mice. In addition, transcriptome analysis revealed that crocin-I was effective in mediating the amelioration of lipid metabolism, mainly in fatty acid metabolism and steroid biosynthesis in CORT-treated mice. Moreover, metabolome analysis demonstrated that crocin-I could restore the disturbed metabolites in the liver of CORT-treated mice, most of which are long-chain fatty acids. Furthermore, high-throughput sequencing of 16s rRNA revealed that crocin-I could mitigate the dysbiosis of the gut microbiota caused by CORT at a dose of 40 mg kg-1, by resulting in a significant increase in the alpha diversity of the microbes in the cecal contents and a significant reduction in the abundance of Firmicutes, whereas by increasing the abundance of Bacteroidetes. These results indicated that oral administration of crocin-I could modify the composition of the gut microbiota and alleviate hepatic lipid disorder in mice treated with a high dose of GCs.

Steroid biosynthesis and Leydig cell morphology in adult unilaterally cryptorchid rats

Abstract: Unilateral cryptorchidism was induced in newborn rats and when the rats reached adult age Leydig cell morphology and steroid biosynthesis were compared in scrotal and abdominal testes. The cell profile area of abdominal Leydig cells was reduced, the cytoplasm contained an increased number of lipid droplets and the endoplasmatic reticulum was more sparse than in scrotal Leydig cells. The intratesticular concentrations of progesterone, 20 alpha-dihydroprogesterone, 17 alpha-hydroxyprogesterone and testosterone were measured both basally and after LH stimulation. The synthesis of testosterone was subnormal in the abdominal testes. The data on basal steroid concentrations suggest a block at the 17 alpha-hydroxylase level, but observations after LH stimulation suggest that earlier steps are also involved. When studied in vitro the steroid biosynthesis in abdominal testes was also disturbed. The conversion mediated by 17 alpha-hydroxylase and 17 beta-ketosteroid reductase was lower and the conversion mediated by 20 alpha-dehydrogenase was higher in the abdominal testis. The reason for the disturbed steroid biosynthesis in abdominal testes is unknown. It may be related to the increased concentration of oestradiol in abdominal testes. Other possibilities are altered paracrine influence from the damaged tubules or changes in the microcirculation of the testis.

Intestinal Transcriptome Analysis Reveals Soy Derivative-Linked Changes in Atlantic Salmon.

Abstract: Intestinal inflammation in farmed fish is a non-infectious disease that deserves attention because it is a major issue linked to carnivorous fishes. The current norm is to formulate feeds based on plant-derived substances, and the ingredients that have antinutritional factors are known to cause intestinal inflammation in fishes such as Atlantic salmon. Hence, we studied inflammatory responses in the distal intestine of Atlantic salmon that received a feed rich in soybean derivatives, employing histology, transcriptomic and flow cytometry techniques. The fish fed on soy products had altered intestinal morphology as well as upregulated inflammation-associated genes and aberrated ion transport-linked genes. The enriched pathways for the upregulated genes were among others taurine and hypotaurine metabolism, drug metabolism-cytochrome P450 and steroid biosynthesis. The enriched gene ontology terms belonged to transmembrane transporter- and channel-activities. Furthermore, soybean products altered the immune cell counts; lymphocyte-like cell populations were significantly higher in the whole blood of fish fed soy products than those of control fish. Interestingly, the transcriptome of the head kidney did not reveal any differential gene expression, unlike the observations in the distal intestine. The present study demonstrated that soybean derivatives could evoke marked changes in intestinal transport mechanisms and metabolic pathways, and these responses are likely to have a significant impact on the intestine of Atlantic salmon. Hence, soybean-induced enteritis in Atlantic salmon is an ideal model to investigate the inflammatory responses at the cellular and molecular levels.

Seasonal variation in steroid biosynthesis by the testis of the lizard Tiliqua Rugosa.

Abstract: 1. Seasonal change in the biosynthesis of androgens by testicular tissue from a scincid lizard Tiliqua rugosa has been studied in vitro using [7-3H]pregnenolone and [4-14C]progesterone as substrates. 2. Evidence is presented for the synthesis of epitestosterone, testosterone, androstenedione, 17 alpha-hydroxyprogesterone, 20 beta-hydroxypregn-4-en-3-one, and 17 alpha, 20 beta-dihydroxypregn-4-en-3-one. 3. Epitestosterone was the major conversion product. Its yield was highest (68%) during summer and lowest (14%) during spring. The yield of testosterone was maximal (10%) during spring (mating season). The production of 20 beta-hydroxypregn-4-en-3-one was highest during spring and undetectable during summer. 4. Histological evidence and changes in testicular weight indicated that spermatogenic activity was greatest during spring. Pronounced regression of the testis occurred immediately after the breeding season and lasted until autumn.