Effects of serum and lipoproteins on steroidogenesis in cultured bovine luteal cells

Role of lipoproteins and de-novo cholesterol synthesis in progesterone production by cultured bovine luteal cells

“…As previously reported by Pate & Condon (1982), cultured bovine luteal cells respond to both LDL and HDL although the present study shows that LDL is 7 times more potent on a protein-weight basis and 3-5 times more potent on a basis of cholesterol content. While cells are more sensitive to LDL than HDL, it is not clear which of these two lipoproteins plays the more important role in vivo since HDL is the major lipoprotein class present in bovine serum (Jonas, 1972;Raphael, Dimick & Puppione, 1973).…”

“…Incubation of these cells with HDL either has no effect or causes an actual decrease in steroid synthesis (Tureck & Strauss, 1982), perhaps due to promotion of cholesterol efflux (Wu & Baily, 1980 (Savion, Laherty, Cohen, Lui & Gospodarowicz, 1982). Pate & Condon (1982) have reported that bovine luteal cells will respond to bovine LDL and HDL although the relative potency of these two lipoproteins was not examined. In this study we have examined the sensitivity of cultured bovine luteal cells to LDL and HDL and have assessed the requirement for de-novo cholesterol synthesis by use of compactin, a specific inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reducíase (HMG CoA reducíase), the rate limiting enzyme in cholesterol biosynthesis (Endo, 1981 (Havel, Eder & Bragdon, 1955) using solid KBr for density adjustments.…”

Secretion of prostaglandins and progesterone by cells from corpora lutea of mares

“…It is possible that differences between the present and previous studies may be a function of the culture conditions. For example, it has been shown that LH does not stimulate progesterone production by sheep and cattle luteal cells when they are cultured in a medium containing serum (Pate & Condon, 1982;Hoyer et ai, 1988 (Milvae & Hansel, 1983;Pate & Condon, 1984).…”

Effects of antibiotics and medium supplements on steroidogenesis in cultured cow luteal cells

“…Channing et al (1976) removed serum from pig granulosa cell cultures and reported enhanced luteinization of the cells with the addition of insulin, cortisol and thyroxin. Reports by Pate & Condon (1982) and Orly et al (1980) stated that the addition of serum to culture medium inhibited the response of luteal and granulosa cells to LH and FSH, respectively. Although incapable of responding to gonadotrophins, both cell types are able to respond to cyclic adenosine monophosphate (cAMP) in the presence of serum, suggesting that serum has its inhibitory effect before cAMP accumulation (Orly et al, 1980;Pate & Condon, 1982 Removal of serum necessitates the addition of supplements to meet the physiological require¬ ments of the cells.…”