Thomas J. Collin's Home Page

Thomas J. Collins, Ph.D.

Research in my laboratory at the University of Texas Medical Branch in Galveston, TX, is directed toward the understanding of various reproductive related pituitary-hypothalamic (PH) interactions. There are three main research thrusts, specifically, independent, collaborative, and Radioimmunoassay core facility. Teaching activities are in the graduate school and medical school. Currently two graduate students (from another laboratory) and one medical student use my laboratory to perform part of their research.

Credentials

Research Program

My personal research is an ongoing, fifteen year, quest to determine the affects of age on the PH axis. Mammals lose the ability to produce offspring by middle age, at a time when their ovaries are not depleted of eggs. My specific thrust is to examine the role of the preovulatory LH surge in this premature loss of reproductive function.

Using rodent animal models, I and others have demonstrated that the PH complex exhibits reduced and impaired abilities to sustain episodic releases of LH, a necessary function in producing effective LH surges for triggering ovulation.

My research has revealed that the acute phase or rising phase of the LH surge (secretion of readily-releasable pool) is not affected by age, but the sustained or plateau phase is greatly impaired by middle age. This latter phase depends upon processing of presynthesized stores of LH as well newly synthesized LH. This "protein-synthesis" dependent phase can be blocked by protein synthesis inhibitors at both the transcription and translation steps. The use of such substances effectively mimics the secretory patterns of LH found in aging animals. Furthermore, I have shown that impaired secretory function of aging animals correlates with parallel reductions in anterior pituitary message production for LH-beta , the synthesis limiting message for LH.

Interesting, reductions in message to alpha -tubulin, a cytoskeletal elements, were also found leading to the conclusion that impaired LH secretory function in aging animals is caused by hormone synthesis impairments as well as possible problems in transportation of LH secretory granules for secretion.

Additional Information

Laboratory Techniques: Northern Blot Analysis, Radioimmunoassay. Additional interest include the development of computer based teaching programs for the teaching of gross anatomy, a dying discipline, that this faculty still encourages graduate students to take.

Recent Publications

Collins, T.J. The use of mouse pituitary fragments to study LH secretion. Endocrine Research, 16: 107-133, 1990.

Collins, T.J. and Parkening, T.A. Exposure to estradiol impairs luteinizing hormone function during aging. Mechanisms of Aging and Development, 58: 207-220, 1990.

Collins, T.J. and Miller, B.T. PItuitary message to LH decreases by middle age in female mice that display impaired LH- function. The Endocrine Society, Abstract 1264, 1993.

Collins, T.J., Given, R.L., Hulsebosch, C.E. and Miller, B.T. Status of gross anatomy in the U.S. and Canada: Dilemma for the 21st Century. Clinical Anatomy, 7: 275-296, 1994.

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Last updated: 05/20/03