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Studies Concerning the Renotropic Action of Pituitary Extracts1
STUDIES CONCERNING THE RENOTROPIC ACTION OF PITUITARY EXTRACTS 1 HANS SELYE
AND
CHARLOTTE HOLLETT
From the Department of Anatomy, McGill University, Montreal, Canada
It is now definitely established that a large number Qf steroid compounds possesses the power of stimulating the growth of the renal tubules (Selye '43). This action is not entirely mediated by the pituitary since renotropic steroids cause some kidney enlargement even in the hypophysectomized animal. However, their renotropic action is much more pronounced if the pituitary is present (Selye '41). These observations are compatible with the view that the renotropic steroids can stimulate the kidney both directly and by eliciting an increased secretion of renotropic pituitary hormones. It is also possible that the renotropic steroids have no influence upon the hormone secretion of the pituitary, but that the kidney tissue is especially responsive to them if normal amounts of hypophyseal renotropic hormone is present in the body. Further experiments will be necessary to establish which of these theoretical explanations is correct, but in any case it is evident that pituitary hormones play an important role in the maintenance of normal kidney size. Further evidence concerning the existence of a pituitary renotropic hormone has been furnished by experiments showing that hypophysectomy inhibits the regeneration of kidney tissue in unilaterally nephrectomized rats (Selye et al. '34, McQueenWilliams and Thompson '40). Similar observations have been made in the toad (Gonzales '38a, 38b) and in the dog (Winterriitz and Waters '40). More recently it has been found that it is possible to prepare extracts which imitate either the renotropic or the nephrosclerotic action of steroids (Selye '44). It remains to be shown whether these pituitary preparations have a direct effect upon the kidney or whether they act merely because they stimulate the elaboration of renotropic and nephrosclerosis-producing steroids. It will be recalled that the most active renotropic compounds are found among the testoid androstane derivatives, while the most potent nephrosclerosis-producing compound is a corticoid hormone namely, desoxycorticosterone. It is not within the scope of this communication to discuss the nephrosclerosis-producing potency, but it should be pointed out that pituitary preparations exert a definite renotropic effect even in the absence of the testis (Selye '44). Hence it is rather probable that their effect is not completely dependent upon stimulation of testicular hormone production. Since hypophyseal preparations capable of stimulating kidney growth might become valuable therapeutic agents, we decided to investigate their effect under experimental conditions designed to imitate certain clinically important kidney lesions. We knew from previous work that the pressure atrophy of the kid1 The material of this communication formed part of the Annual B. A. Thomas Oration delivered by one of us before the Philadelphia Urological Society of the American Urological Association on May 22, 1944. 498
RENOTROPIC ACTION OF PITUITARY EXTRACTS
ney, ·which is usually produced by ligature of the ureter, is greatly delayed by renotropic steroids, such as testosterone (Selye and Friedman '41). It appeared of interest, therefore, to establish whether a pituitary extract with proven renotropic potency l'rnuld exert a similar action. EXPERIMENTAL
Sixteen female albino rats with an initial body weight of 62~ 108 g. (average 82 g.) were divided into two equal groups consisting of 8 animals each. The left ureter was completely transected between 2 ligatures in all animals of both groups; but while the rats of the first group received no further treatment and acted as controls, those of the second group were given 2 daily subcutaneous injections of 20 mg. of lyophilized cattle anterior lobe tissue suspended in 0.2 cc of physiological saline solution. It ,Yill be recalled that such lyophilized anterior lobe tissue, prepared by the freezing-drying technic, readily forms fine suspensions in water and retains the pituitary proteins (and presumably all pituitary hormones) in a practically unaltered condition. Preparations of this type are, therefore, highly suitable when it is desired to overdose with all anterior lobe principles. Experiments concerning the fractionation and purification of the renotropic anterior lobe principle are now under way in this laboratory, but this work has not proceeded far enough as yet to state with certainty whether the renotropic hormone is a separate principle or whether this action on the kidney is merely a side-effect of one of the already known hypophyseal hormones. In view of this uncertainty it appeared best to usc lyophilized anterior lobe tissue in the present experimental series in which maximum potency, rather than purity of the preparation, was of primary importance. Following 20 days of treatment the animals of both groups were killed. At this time the body weight of the treated rats was 161 g. and that of the untreated rats 104 g. on the average. The increased growth rate of the treated rats shows that our preparation ,ms potent with regard to somatotropic (growth hormone) effect. At autopsy it became immediately evident that in the treated rats the renal pelves were much more dilated with urine than in the untreated controls. This, we believe, indicates that on the side bearing the ligature urine secretion against pressure proceeded longer than usual as a result of our treatment. The macroscopically recognizable kidney tissue was then separated from the renal pelvis and the pericapsular connective tissue adhesions. The comparatively normal kidney tissue thus obtained was subsequently weighed on an analytical balance and its average ,Yeight was found to be 57G mg. in the untreated controls and 999 mg. in the rats receiving the pituitary preparation. Histological examination of the kidney likewise showed a clear-cut stimulation as a result of the treatment inasmuch as the renal tissue of the untreated controls lost its structure almost completely, there being only a thin shell of fibrouR tissue with some remnantR of atrophic tubules and glorneruli. On the other hand, in the rats receiving the pituitary preparation the general appearance of the renal tissue was still very well preserved although the renal pelvis was greatly distended and hence the gross shape of the kidney was abnormal (figs. 1 and 2). Under
500
HANS SEL YE .\ND CH-\RLOTTE HOLLETT
higher magnification the difference between the two groups was still more obvious. In the untreated controls the epithelial cells of the convoluted tubules were very well developed and only occasionally could we detect atrophic areas. The glomeruli \vere like1Yise well preserved and perhaps even some\\·hat enlarged.
FIG. 1. Low magnification of a cross-section through a rat kidney 20 days after ureter ligature. Note marked atrophy of renal tissue which is reduced to a very thin layer.
FIG. 2. Cross-section through a rat kidney 20 days after ureter ligature. In this animal renal atrophy was inhibited by daily treatment with a renotropic preparation.
The lumina of the convoluted tubules contained no casts but were somewhat distended by the stagnating urine. Conversely, in the untreated controls pressure atrophy of the renal tissue was very pronounced and although the glomeruli were only slightly subnormal in diameter, the tubules showed a considerable degree of involution (figs. 3 and 4).
RENOTROPIC ACTIO:--i OF PITUIT.\RY EXTR.\CTS
:Fm._ 3. Higher magnification of a comparatively well preserved portion of the shown m figure 1. Note marked atrophy of convoluted tubules and cornparativelv glomeruli. · "
:B'rn. 4. Higher magnification of a portion of kidney shown in figure 2. veloped tubules and glorneruli.
X ote well de--
It appears, therefore, that the pressure atrophy of kidney tissue, ,vhich usually occurs follmving obstruction of the ureter, can be greatly delayed. renotropic anterior lobe preparation,;;.
,502
HANS SELYE AND CHARLOTTE HOLLETT
The contralateral normal kidney was also weighed and histologically examined in all cases and it was found that while its average weight in the untreated controls was 808 mg., it was 1401 mg. in the pituitary treated animals. Histologically this increase proved to be due mainly to an enlargement of the convoluted tubules although the average size of the glomeruli was also somewhat increased. SUMMARY
Experiments in female albino rats indicate that under normal conditions, following unilateral ligature of the ureter, marked pressure atrophy of the kidney tissue ensues within twenty days. This atrophy is inhibited by daily treatment with a preparation made from the anterior lobe of the cattle hypophysis. Acknowledgment: The expenses of these investigations were defrayed through a grant received from the DesBergers-Bismol Laboratories. REFERENCES GoNZALE'z, RODOLFO: Influenzia de la hipofisis sobre la hipertrofia renal compensadora. Rev. Soc. Argentina de Biol., 14: 173, 1938, a. - - - : Action de l'hypophyse sur l'hypertrophie renale compensatrice chez Jes batraciens. Compt. rend. Soc. de biol., 129: 1270, 1938, b. McQuEEN-WILLIAMS, M. AND THOMPSON, K. W.: The effect of ablation of the hypophysis upon the weight of the kidney of the rat. Yale J. of Biol. & Med., 12: 531, 1940. SELYE, HANS: Effect of hypophysectomy on the morphological appearance of the kidney and on the renotropic action of steroid hormones. J. Urol., 46: 110, 1941. - - - - : Encyclopedia of Endocrinology, A. W. T. Franks Publishing Company, Montreal, 1943. Section I. Classified index of the steroid hormones and related compounds. - - - - : Role of the hypophysis in the pathogenesis of the diseases of adaptation. Canad. J\L A. J., 50: 426, 1944. - - - - , AND FRIEDMAN, S. M.: The beneficial action of testosterone in experimental renal atrophy caused by ligature of the ureter. Endocrinology, 29: 80, 1941. - - - , MORTIMER, H. H., THOMSON, D. L. AND CoLLIP, J.B.: Effect of parathyroid extract on the bones of the hypophysectomized rat. A histologic study. Arch. Path., 18: 878, 1934. WINTERNITZ, M. C. AND WATERS, L. L.: The effect of hypophysectomy on compensatory renal hypertrophy in dogs. Yale J. Biol. & Med., 12: 705, 1940.
AND
CHARLOTTE HOLLETT
From the Department of Anatomy, McGill University, Montreal, Canada
It is now definitely established that a large number Qf steroid compounds possesses the power of stimulating the growth of the renal tubules (Selye '43). This action is not entirely mediated by the pituitary since renotropic steroids cause some kidney enlargement even in the hypophysectomized animal. However, their renotropic action is much more pronounced if the pituitary is present (Selye '41). These observations are compatible with the view that the renotropic steroids can stimulate the kidney both directly and by eliciting an increased secretion of renotropic pituitary hormones. It is also possible that the renotropic steroids have no influence upon the hormone secretion of the pituitary, but that the kidney tissue is especially responsive to them if normal amounts of hypophyseal renotropic hormone is present in the body. Further experiments will be necessary to establish which of these theoretical explanations is correct, but in any case it is evident that pituitary hormones play an important role in the maintenance of normal kidney size. Further evidence concerning the existence of a pituitary renotropic hormone has been furnished by experiments showing that hypophysectomy inhibits the regeneration of kidney tissue in unilaterally nephrectomized rats (Selye et al. '34, McQueenWilliams and Thompson '40). Similar observations have been made in the toad (Gonzales '38a, 38b) and in the dog (Winterriitz and Waters '40). More recently it has been found that it is possible to prepare extracts which imitate either the renotropic or the nephrosclerotic action of steroids (Selye '44). It remains to be shown whether these pituitary preparations have a direct effect upon the kidney or whether they act merely because they stimulate the elaboration of renotropic and nephrosclerosis-producing steroids. It will be recalled that the most active renotropic compounds are found among the testoid androstane derivatives, while the most potent nephrosclerosis-producing compound is a corticoid hormone namely, desoxycorticosterone. It is not within the scope of this communication to discuss the nephrosclerosis-producing potency, but it should be pointed out that pituitary preparations exert a definite renotropic effect even in the absence of the testis (Selye '44). Hence it is rather probable that their effect is not completely dependent upon stimulation of testicular hormone production. Since hypophyseal preparations capable of stimulating kidney growth might become valuable therapeutic agents, we decided to investigate their effect under experimental conditions designed to imitate certain clinically important kidney lesions. We knew from previous work that the pressure atrophy of the kid1 The material of this communication formed part of the Annual B. A. Thomas Oration delivered by one of us before the Philadelphia Urological Society of the American Urological Association on May 22, 1944. 498
RENOTROPIC ACTION OF PITUITARY EXTRACTS
ney, ·which is usually produced by ligature of the ureter, is greatly delayed by renotropic steroids, such as testosterone (Selye and Friedman '41). It appeared of interest, therefore, to establish whether a pituitary extract with proven renotropic potency l'rnuld exert a similar action. EXPERIMENTAL
Sixteen female albino rats with an initial body weight of 62~ 108 g. (average 82 g.) were divided into two equal groups consisting of 8 animals each. The left ureter was completely transected between 2 ligatures in all animals of both groups; but while the rats of the first group received no further treatment and acted as controls, those of the second group were given 2 daily subcutaneous injections of 20 mg. of lyophilized cattle anterior lobe tissue suspended in 0.2 cc of physiological saline solution. It ,Yill be recalled that such lyophilized anterior lobe tissue, prepared by the freezing-drying technic, readily forms fine suspensions in water and retains the pituitary proteins (and presumably all pituitary hormones) in a practically unaltered condition. Preparations of this type are, therefore, highly suitable when it is desired to overdose with all anterior lobe principles. Experiments concerning the fractionation and purification of the renotropic anterior lobe principle are now under way in this laboratory, but this work has not proceeded far enough as yet to state with certainty whether the renotropic hormone is a separate principle or whether this action on the kidney is merely a side-effect of one of the already known hypophyseal hormones. In view of this uncertainty it appeared best to usc lyophilized anterior lobe tissue in the present experimental series in which maximum potency, rather than purity of the preparation, was of primary importance. Following 20 days of treatment the animals of both groups were killed. At this time the body weight of the treated rats was 161 g. and that of the untreated rats 104 g. on the average. The increased growth rate of the treated rats shows that our preparation ,ms potent with regard to somatotropic (growth hormone) effect. At autopsy it became immediately evident that in the treated rats the renal pelves were much more dilated with urine than in the untreated controls. This, we believe, indicates that on the side bearing the ligature urine secretion against pressure proceeded longer than usual as a result of our treatment. The macroscopically recognizable kidney tissue was then separated from the renal pelvis and the pericapsular connective tissue adhesions. The comparatively normal kidney tissue thus obtained was subsequently weighed on an analytical balance and its average ,Yeight was found to be 57G mg. in the untreated controls and 999 mg. in the rats receiving the pituitary preparation. Histological examination of the kidney likewise showed a clear-cut stimulation as a result of the treatment inasmuch as the renal tissue of the untreated controls lost its structure almost completely, there being only a thin shell of fibrouR tissue with some remnantR of atrophic tubules and glorneruli. On the other hand, in the rats receiving the pituitary preparation the general appearance of the renal tissue was still very well preserved although the renal pelvis was greatly distended and hence the gross shape of the kidney was abnormal (figs. 1 and 2). Under
500
HANS SEL YE .\ND CH-\RLOTTE HOLLETT
higher magnification the difference between the two groups was still more obvious. In the untreated controls the epithelial cells of the convoluted tubules were very well developed and only occasionally could we detect atrophic areas. The glomeruli \vere like1Yise well preserved and perhaps even some\\·hat enlarged.
FIG. 1. Low magnification of a cross-section through a rat kidney 20 days after ureter ligature. Note marked atrophy of renal tissue which is reduced to a very thin layer.
FIG. 2. Cross-section through a rat kidney 20 days after ureter ligature. In this animal renal atrophy was inhibited by daily treatment with a renotropic preparation.
The lumina of the convoluted tubules contained no casts but were somewhat distended by the stagnating urine. Conversely, in the untreated controls pressure atrophy of the renal tissue was very pronounced and although the glomeruli were only slightly subnormal in diameter, the tubules showed a considerable degree of involution (figs. 3 and 4).
RENOTROPIC ACTIO:--i OF PITUIT.\RY EXTR.\CTS
:Fm._ 3. Higher magnification of a comparatively well preserved portion of the shown m figure 1. Note marked atrophy of convoluted tubules and cornparativelv glomeruli. · "
:B'rn. 4. Higher magnification of a portion of kidney shown in figure 2. veloped tubules and glorneruli.
X ote well de--
It appears, therefore, that the pressure atrophy of kidney tissue, ,vhich usually occurs follmving obstruction of the ureter, can be greatly delayed. renotropic anterior lobe preparation,;;.
,502
HANS SELYE AND CHARLOTTE HOLLETT
The contralateral normal kidney was also weighed and histologically examined in all cases and it was found that while its average weight in the untreated controls was 808 mg., it was 1401 mg. in the pituitary treated animals. Histologically this increase proved to be due mainly to an enlargement of the convoluted tubules although the average size of the glomeruli was also somewhat increased. SUMMARY
Experiments in female albino rats indicate that under normal conditions, following unilateral ligature of the ureter, marked pressure atrophy of the kidney tissue ensues within twenty days. This atrophy is inhibited by daily treatment with a preparation made from the anterior lobe of the cattle hypophysis. Acknowledgment: The expenses of these investigations were defrayed through a grant received from the DesBergers-Bismol Laboratories. REFERENCES GoNZALE'z, RODOLFO: Influenzia de la hipofisis sobre la hipertrofia renal compensadora. Rev. Soc. Argentina de Biol., 14: 173, 1938, a. - - - : Action de l'hypophyse sur l'hypertrophie renale compensatrice chez Jes batraciens. Compt. rend. Soc. de biol., 129: 1270, 1938, b. McQuEEN-WILLIAMS, M. AND THOMPSON, K. W.: The effect of ablation of the hypophysis upon the weight of the kidney of the rat. Yale J. of Biol. & Med., 12: 531, 1940. SELYE, HANS: Effect of hypophysectomy on the morphological appearance of the kidney and on the renotropic action of steroid hormones. J. Urol., 46: 110, 1941. - - - - : Encyclopedia of Endocrinology, A. W. T. Franks Publishing Company, Montreal, 1943. Section I. Classified index of the steroid hormones and related compounds. - - - - : Role of the hypophysis in the pathogenesis of the diseases of adaptation. Canad. J\L A. J., 50: 426, 1944. - - - - , AND FRIEDMAN, S. M.: The beneficial action of testosterone in experimental renal atrophy caused by ligature of the ureter. Endocrinology, 29: 80, 1941. - - - , MORTIMER, H. H., THOMSON, D. L. AND CoLLIP, J.B.: Effect of parathyroid extract on the bones of the hypophysectomized rat. A histologic study. Arch. Path., 18: 878, 1934. WINTERNITZ, M. C. AND WATERS, L. L.: The effect of hypophysectomy on compensatory renal hypertrophy in dogs. Yale J. Biol. & Med., 12: 705, 1940.