عنوان

Immunocytochemical localization of gonadotropins, growth hormone, and prolactin in equine pituitary

Number

TLpq304305891

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Immunocytochemical localization of gonadotropins, growth hormone, and prolactin in equine pituitary

General Material Designation

[Thesis]

First Statement of Responsibility

M. S. Rahmanian

Subsequent Statement of Responsibility

D. L. Thompson, Jr.

Name of Publisher, Distributor, etc.

Louisiana State University and Agricultural & Mechanical College

Date of Publication, Distribution, etc.

1996

Specific Material Designation and Extent of Item

154

Dissertation or thesis details and type of degree

Ph.D.

Body granting the degree

Louisiana State University and Agricultural & Mechanical College

Text preceding or following the note

1996

Text of Note

The present research was performed to characterize immunoreactive (ir) pituitary cells in the equine species. Two experiments were performed to measure the prevalence of single- and double-hormone labeled gonadotropes, lactotropes, somatotropes, and mammosomatotropes. In Experiments 1 and 2, pituitaries from three intact pony mares were processed for ultrastructural evaluation of cells stained for luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and growth hormone (GH). Primary antibodies and gold-conjugated antibodies were used to double-stain ir-cells. The percentages of pituitary cells stained for each hormone in intact mares were: total gonadotropes, 15 to 32%; LH-only, 2 to 16%; FSH-only, 1 to 5%; LH/FSH, 6 to 24%; GH-only, 11 to 26%; PRL-only, 5 to 16%; and GH/PRL, 7 to 17%. In Experiments 3 and 4, long-term ovariectomized (OVX) mares (n = 4/group) were injected with vehicle, estradiol (35 mug/kg), or dihydrotestosterone (DHT; 150 mug/kg) for 21 days. Immunoreactive-cells were identified immunocytochemically and pituitary content of LH, FSH, GH, and PRL and plasma concentrations of LH, FSH, and PRL were measured. DHT reduced (P usdusd.1) on plasma PRL. Estradiol reduced (P usdusd.1) on plasma LH. The percentages of pituitary cells which stained for each hormone in control OVX mares were: total gonadotropes, 12%; LH/FSH, 9%; LH- or FSH-only, 2%; total lactotropes, somatotropes, and mammosomatotropes, 50%; GH-only, 22%; PRL-only, 23%; and GH/PRL, 6%. Estradiol treatment increased (P <.05) pituitary concentrations of LH, FSH and PRL. Estradiol also reduced (P <.05) the number of cells stained for LH/FSH and increased (P <.05) the number of lactotropes and mammosomatotropes. DHT reduced (P <.05) pituitary concentrations of LH and FSH but did not significantly affect tissue concentrations of PRL or GH. DHT reduced (P <.05) the number of cells that stained for LH/FSH and it increased (P <.05) the number of FSH-only cells. It is concluded that equine pituitary gonadotropes are subdivided into cells which contain one or both gonadotropins; and PRL and GH also, can be found in separate cells or in same secretory granules within one cell. Furthermore, OVX and steroid treatment preferentially regulate hormone secretion from gonadotropes that produce both LH and FSH as well as the number of ir-lactotropes and mammosomatotropes.

Anatomy & physiology

Anatomy & physiology

Animals

Biological sciences

Cellular biology

Livestock

D. L. Thompson, Jr.

M. S. Rahmanian

Electronic name

p

[Thesis]

276903

a

Y