Role of luteinizing hormone in luteotropic complex of pregnant hamster
Hamsters were hypophysectomized on day 4 of pregnancy and injected subcutaneously on days 4-7 with various combinations of 200 ..mu..g prolactin (Prl), 10 ..mu..g follicle-stimulating hormone (FSH), and 20 ..mu..g luteinizing hormone (LH) in polyvinylpyrrolidone (PVP) to decrease its rate of absorption or in saline. End points for luteal function on day 8 were maintenance of pregnancy, serum progesterone (P/sub 4/), luteal weight, and luteal binding for human chorionic gonadotropin, FSH, and Prl. After hypophysectomy, a drastic decline occurred in all parameters including an 89% decrease in luteal weight. Injection of Prl did not maintain pregnancy nor serum P/sub 4/ but partially maintained luteal weight and human chorionic gonadotropin binding sites per corpus luteum. The minimal luteotropic complex of Prl and FSH was effective in maintaining pregnancy and significantly increased serum P/sub 4/ and Prl and FSH receptors but not to control levels. Thus, the luteotropic activity of LH was only demonstrable when it was injected in a long-acting form; when delivered as a bolus, LH (saline) was luteolytic. P/sub 4/ and estradiol were measured by radioimmunoassay. Radioiodinated gonadotropins were prepared. The percentage of tracer reacting with an excess of receptor were 51% of /sup 125/I-FSH and 45.9% of /sup 125/I-hCG using whole homogenates of hamster ovaries.
- Research Organization:
- Univ. of Kansas, Kansas City
- OSTI ID:
- 5767121
- Journal Information:
- Am. J. Physiol.; (United States), Vol. 252:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ESTRADIOL
RADIOIMMUNOASSAY
GONADOTROPINS
CONFIGURATION INTERACTION
LABELLED COMPOUNDS
PROGESTERONE
CELL MEMBRANES
FSH
HAMSTERS
IODINE 125
LH
LIVER
LTH
OVARIES
PREGNANCY
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
ESTRANES
ESTROGENS
FEMALE GENITALS
GLANDS
GONADS
HORMONES
HYDROXY COMPOUNDS
IMMUNOASSAY
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
MAMMALS
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PREGNANES
RADIOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
RODENTS
STEROID HORMONES
STEROIDS
TRACER TECHNIQUES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics