DISCUSSION 



Chairman : Roy O. Creep 



Dr. John Hammond, Jr. : I have one idea that I should like to put to you because it follows 

 what was said about ovulation. 



Dr. Noyes seems to disregard the effect of the intra-ocular pressure, and it seems to 

 me that that might be of some considerable importance. Ovulation depends upon the 

 formation of the ovulation cone and that cone formation, I suppose, depends upon 

 the occlusion of the vessels. And that point, that occlusion, depends upon the pressure 

 gradient across the wall of the follicle. 



Now, I have heard the follicle picturesquely described as a blister on the surface of 

 the ovary, and I think that is more than a figure of speech. We think of the liquor as 

 secretion of the cells. It is in part, particularly in the early stages when you have a lot 

 of cells and cement substance around the oocyte, a viscous sort of fluid; but, in the 

 later stages of the follicle, you get rapid accumulation of fluid, of tertiary liquor. 



Some Italians (R. Catavaglios and R. Cilotti, /. Endocrinol 15, 273, 1957) analyzed 

 the liquor and showed that it contains most of the blood proteins; the largest molecules 

 are present in reduced amounts, but it seems more or less to be a transudate from the 

 thecal vessels, and yet collecting amongst the epithelium of the granulosa. This is 

 very much like the foitnation of a blister. You burn yourself, and a fluid is liberated 

 from the blood vessels of the dermis, yet in like manner, the fluid accumulates in the 

 epithelium of the epidermis. If the liquor is a transudate, its formation depends upon 

 the hydrostatic pressure in the blood vessels. 



The intra-ocular pressure in the human eye is about 30 mm of mercury, and the 

 ordinary capillary hydrostatic pressure is of the order of 30 mm of mercury. I don't 

 know what it is in the ovary but it does not seem to be surprising that when you inject 

 pregnancy urine, the follicle doesn't grow so rapidly as it does in its normal position 

 because there is obviously much greater pressure opposing the filtration of the liquor. 



Dr. Noyes also said that the two phenomena of the maturation of the eggs and of 

 ovulation were not necessarily due to the same causes. But I wonder if the stimulus 

 to ovulate which the follicle gets may not produce the maturation of the oocyte and 

 liberate it from the follicle wall, and induce the secretion of the tertiary-liquor, all 

 by the same mechanism. Whether, in fact, the stimulus to ovulate may produce an 

 incipient process of degeneration in the granulosa cells, and that this, on the one 

 hand, liberates the ovum from the wall of the follicle, and at the same time it may also, 

 perhaps, free the ovum from an inhibition of cleavage and allow it to go through the 

 reduction division. Perhaps the degenerating cells release a substance which increases 

 the permeability of the thecal vessel walls, and this results in the sudden increase 

 in pressure and accumulation of fluid, inside the follicle. 



I think one might, perhaps, understand the way in which the pituitary works in 

 inducing ovulation, if one could reconstruct the way in which the process has evolved. 

 For that, I can see two main clues, and perhaps there are many others. One is this : It 

 seems very improbable that FSH and LH should have appeared simultaneously as 

 hormones regulating the process of ovulation. Secondly, one has the probability that 

 the steroid hormones started as gonadal organizer substances. Working from this, 

 I would like to put forward an idea. Initially, I suppose that the ovary was regulated 

 purely by nutrition. I suppose the gonad was a late-developing part of the body. 

 It only developed fully when feeding conditions and nutritive conditions were good. 

 When it did, the germ cells developed and were surrounded by the satellite cells; and 

 when the oocytes were full-grown they went automatically, as cells have a habit of 



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