J. M. Wolfe

Prostatic Type of Paraurethral Glands Induced in Female Rats by Administration of Male Sex Hormone.

Summary 1. Skenes ducts in the female rat are usually rudimentary. Male hormone substance stimulates growth of these glands to a condition which resembles grossly and histologically the prostate of the male rat. 2. In the present series the incidence of these glands in 35 normal animals is 9.4%, in 13 oestrone-injected animals 0%, in 48 male hormone-injected animals 58.3%. 3. The state of Skenes ducts may be utilized as an indicator of the presence of male hormone. 4. In view of the growth response to male but not to female hormones, the occasional finding of Skenes ducts in an uninjected female rat suggests the presence of male hormone in the normal female. 5. The growth response of the female prostatic glands to the male hormone is further evidence of the masculinizing effect of male hormone substance of the female animal.

Reaction of Anterior Hypophysis of Immature Rat to Placental Hormones.

Lehmann 1 has reported that injection of placental extracts brings about pregnancy changes in the anterior hypophysis of the female rat. Collip and his associates 2 have recently reported that long term injection of the anterior-pituitary-like hormone of the placenta brings about an enlargement of the anterior hypophysis, which is later followed by a decrease. We have carried out a series of experiments in which we have studied the histological changes in the anterior pituitaries of immature rats which had received injections of a relatively crude oestrin-free extract of placenta. The method of preparation of this extract has been described. 3 We have used litters of immature female rats, 25 to 35 days old. Half of the animals in each litter received 2 subcutaneous injections daily for 6 to 8 days. The remaining animals in the litter served as controls. The results of the injections were constant and definite. Table I illustrates some of our findings and shows that the ovaries of the injected animals were markedly increased in size.† The swollen and hyperemic pituitaries of the injected animals exhibited a moderate but invariable weight increase when compared with those of the controls. The ovaries and pituitaries of all animals were weighed on a torsion balance accurate to 0.5 mg. (Hartmann and Braun). Analysis of Table I reveals that the increase in the size of the hypophysis was as a rule greatest in the animals in which the ovarian reaction was greatest, a fact already noted by Collip and associates. Complete serial sections of the hypophyses of both the control and experimental animals were cut. One section from each ribbon of 25 was mounted, giving a complete set of sections. Every fifth or sixth slide of each set of sections was studied.

Reactions of Ant. Pituitaries of Male Rats to Administration of Ant. Pituitary-Like Substance and to Oestrin.∗

Recent studies 1 indicated that injections of massive amounts of oestrin into normal female rats induced weight and morphologic reactions in the anterior pituitary similar to those obtained by the injection of the anterior pituitary-like substance of pregnancy urine. Both of these substances induced a marked weight increase in the gland, a marked loss of granules from the basophiles and a less evident loss of granules from the eosinophiles (in A.P.L. rats whose ovaries contained active corpora lutea). Furthermore, it has been found that administration of the A. P. L. factor has no action on the anterior hypophysis of the castrated rat 2 , 3 but that oestrin is capable of direct action on the anterior lobe of the castrated rat. 4 The experiments described below were carried out in order to compare the reaction of normal male rat pituitaries to administration of these 2 factors. Fourteen adult male rats received daily injections of 25 rat units of an extract of pregnancy urine† for 10 days. Another group of 10 rats received daily injections of 200 rat units of oestrin† for 10 days. A third group of 30 normal mature male rats served as controls. At autopsy, body, pituitary, testes and prostate and seminal vesicle weights were secured. Serial sections of all glands were cut. 5 representative sections from each series were studied and cell counts made. Quantitative results are presented in Table I. Administration of the A. P. L. substance to male rats did not increase the weight of the pituitary gland over that found in the controls (Table I). This was in contrast to previous findings in female rats. Confirming the findings of Severinghaus 2 the anterior pituitaries of the injected male rats exhibited a marked loss of granules from practically all the basophiles although a few granular basophiles were present (Table I).

Reaction of Anterior Pituitaries of Immature Female Rats to Injections of Various Amounts of Oestrin.

It is well established that injection of oestrin in normal female rats induces changes in the anterior hypophysis comparable to those of pregnancy and that such injections in castrated female rats prevent typical castration changes. Daily injection of large amounts of oestrin into normal female rats for 10 days results in a marked but variable weight increase in the pituitaries. The basophiles are markedly degranulated and reduced in relative percentage. The eosinophils also present loss of granules and a variable reduction in relative percentage. The chromophobes are greatly increased in relative percentage. 1 In the studies recorded below we have attempted to ascertain more exactly the morphologic and quantitative effects of large and small daily injection of oestrin for periods of 5 and 10 days on the various cell types of the anterior pituitaries of immature female rats. We wished to determine if the amounts of oestrin necessary to cause changes in one cell type would induce changes in the other types. Female rats, 21 to 23 days old were used. At autopsy, body, ovary and pituitary weights were obtained. Serial sections of all pituitaries were cut. Five representative sections from each were studied; differential cell counts were made on each; the number of mitoses were also counted. In the first series, 9 rats received daily injection of 10 units of oestrin† for 5 days; a second group of 8 littermates received daily injection of 200 units for the same period. Eleven littermate controls were available. In the rats receiving, 10 units daily the pituitaries were increased in weight to a mean of 3.5 mg.; the mean in the controls was 2.6 mg. The basophiles of the injected rats were moderately degranulated; the result was a decrease in the relative levels of the granular basophiles to a mean of 2.8% while this mean in the controls was 8.3%. A few of the eosinophiles in the injected rats were swollen and showed loss of granules. The relative percentages of eosinophiles were not decreased when compared with the controls. This may possibly be explained by the fact that in the injected rats the number of mitoses found in the eosinophiles was much greater than in the controls; the mean number per section in the injected rats was 14.7 while in the controls it was only 3.2. The mean number of mitoses per section in the chromophobes was also increased; in the injected rats it was 18.4 while in the controls it was 7.7.

Ovaries of Immature Female Rats Receiving Pregnancy Urine Extract and Combinations of Pregnancy Urine Extract and Oestrin.

We have previously reported 1 that injections of large amounts of oestrin into mature female rats produced corpora lutea in the ovaries of these animals equal in size to those of pregnant rats. Similar results have been reported by Hohlweg 2 and Selye, Collip and Thomson. 3 Other experiments 3 , 4 , 5 have demonstrated that injection of oestrin simultaneously with A.P.L. (anterior pituitary-like substance) enhances the luteinizing capacity of A.P.L. and its capacity to increase the ovarian weights of immature rats. Hisaw and associates 6 and Lane 7 have demonstrated that injection of oestrin stimulated the production on the luteinizing hormone in the anterior hypophysis. The data presented below support the view that combined injection of oestrin and A.P.L. exerts a much greater effect on the ovaries of immature female rats than do injections of the A.P.L. factor alone. In the first series of experiments a group of immature female rats received a single injection of 25 units of A.P.L.† They were killed 10 days later after no further treatment. A second group, littermate sisters to those above, received a single injection of A.P.L. and beginning on the fourth day following the administration of A.P.L. daily injections of 200 units of oestrin,† until the tenth day following the injection of A.P.L., at which time the rats were sacrificed. As controls for these experimental groups a group of untreated littermate sisters were used.

Effect of Feeding Thyroid on Anterior Hypophysis of the Female Albino Rat.

Summary Twenty-eight female rats were fed amounts of desiccated thyroid ranging from 250 to 1,000 mg. daily. The oestral cycle was suppressed to varying degrees, dependent on the dosage of thyroid. The pituitaries were subnormal in weight. Histologically the anterior lobes exhibited certain changes : most notable was a slight increase in the percentage of the basophiles and a definite increase in the size and granular content of these cells. The granules stained a purple-red which varied to a dull brick-red; in normal female rats (virgin and killed during the normal oestral cycle) the basophiles take a deep blue stain. The changes in the basophiles were most marked in those animals in which the suppression of the oestral cycle n-as most evident.

Reaction of Anterior Pituitaries of Immature and Mature Female Rats to Injection of Pregnancy Urine Extracts

It has been previously reported 1 that injections of an oestrin-free placenta extract, containing the A. P. L. factor, into immature female rats induced a marked increase in the weight of the ovaries and a moderate increase in the weight of the pituitaries. Histologically, the pituitaries of the injected rats showed a slight to moderate decrease in the level of the eosinophiles; a considerable number showed evidence of granular loss. The most evident changes were found in the basophiles, which showed marked evidence of granular depletion. Injection of pregnancy urine extracts into immature female rats gives similar results. Thirty rats, 21 to 25 days old, were given daily injections of pregnancy urine extract† (25 to 75 R. U. daily for 6 to 15 days). Twenty-eight littermate sisters served as controls. The ovaries of the injected rats weighed from 50 to 80 mg., while those of the controls weighed from 15 to 25 mg. The pituitaries of the injected animals were usually, but not invariably, increased in weight. Complete serial sections of all pituitaries were cut, at 2 micra, in the horizontal plane. One section from each ribbon of 15 was mounted and stained. Cell counts were made on 5 sections, equidistant apart from each set of serial sections (110,039 cells were counted on the 208 sections studied). The anterior lobes of the injected animals were definitely altered from those of the controls. The eosinophiles were almost invariably reduced in number, and many of them were swollen and showed granular loss. The most marked changes were found in the basophiles, which showed reduction of granules. There was an increase in the percentage of the chromophobes. Mitoses were found in the chromophobes and eosinophiles of both the injected and control animals; they were more abundant in the injected animals. Mitotic division has never been observed in the basophiles.

Anterior Pituitaries of Infantile Female Rats Receiving Injections of Pregnancy Urine Extract.

Many investigators have demonstrated that injections of pregnancy urine or human placental extracts into immature (21-day or above) female rats result in an increase in the size of the ovaries due to follicular maturation and corpus luteum formation. However, subsequent studies of Selye and Collip 1 have revealed that injection of such extracts into infantile female rats (6 to 8 days) fails to cause follicular maturation and development of corpora lutea, but does result in a marked increase in the size of the thecal cells giving rise to thecal corpora lutea. Collip and associates 2 have found that injection of placental extracts increases the size of the pituitaries of immature female rats (21 days or above) as well as the ovaries. We have confirmed these results, using both extracts of human placentae and pregnancy urine.† 3 - 5 Histologically, the pituitaries of these rats exhibited a marked granular loss from the basophiles and a less evident loss of granules from the eosinophiles. Cell counts revealed that the percentages of the basophiles and eosinophiles were decreased, while that of the chromophobes was increased. Since it has been found that injection of pregnancy urine extract brings about a markedly different ovarian effect in infantile rats (6 to 8 days) it seemed of interest to study the anterior pituitaries of such rats.

Effect of a Diet Low in Salts on Oestrous Cycle of Albino Mouse.

In 1922 Evans and Bishop 1 found that a diet poor in salts had a definite effect on the oestrous cycle of the white rat. They found that on such a diet the experimental animals reached maturity later than their litter-mate controls and that only 15% of the oestrous cycles of these animals were of the 4 or 5 day length as opposed to 48% of those of the control animals. We have carried out similar experiments on the white mouse. The animals used were about 60 days of age. Vaginal smears were made daily for 3 weeks, and all animals not showing cycles of 4 to 5 day length were discarded. They were then divided into experimental and control groups. The following experimental diet was used: Casein 31%, dextrin 41%, Crisco 20%, cod liver oil 3%, yeast 5%. The control animals received the same diet, with the exception that salts were fed at a 7% level and the dextrin reduced to 35%. There was a very definite change in the oestrous cycles of the experimental animals, only 25% of the cycles being of the 4 on 5 day length, while many of the long cycles were 12 to 20 days in length. In the control group, 70% of the cycles were 4 or 5 days in length and in the remaining cycles, only a few were over 7 days in length. The experimental animals grew at a slightly lower rate than the control animals. The difference at the peak of the experiment was 13.75%. In all cases, however, the latter exhibited a rather sleek coat, as contrasted with the coarse, roughened fur of the experimental mice. It is evident from these experiments that the oestrous cycle was affected much more than the growth ability, indicating that the oestrous cycle is a much more delicate indicator of the well-being of the animal than is the growth curve.