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1582. Aminopyrine: Poor cow?
434
BIOCHEMICAL PHARMACOLOGY
The next stage of the investigation will be to compare the toxicity of various detergents to the living epidermal cell, a piece of research presenting considerable technical difficulty. 1581. Fighting off the wrinkles Papa, C. M. (1967). Effect of topical hormones on aging human skin. J. Soc. cosmet. Chem. 18, 549. The search for the elixir of youth has been one of mankind's favourite occupations, and it is true that a senescent skin, apart from detracting from the appearance, may impair mental and physical well-being in many people. This aspect of growing old lends interest to the study cited above, in which some 200 residents of a home for the aged, almost all of them suffering from obvious skin degeneration, took part. Areas of skin which showed clear-cut alterations attributable to ageing, including those of the face, extensor forearm, back of hand and axilla, were used to test hydrophilic ointments containing 1% testosterone propionate (I), l°'/o progesterone (II), 0.5% pregnenolone acetate (HI), 0.5~o ethinyl oestradiol (IV), 0.59/o triamcinolone acetonide (V) and 0.2% fluocinolone acetonide (VI). Sometimes alcoholic solutions of the same concentration were used. About 0.5 g of the preparation was applied daily, the vehicle without steroid being applied to the corresponding site on the other side of the body as a control. The sex of the subject did not influence the effects of the hormones on the skin. These effects were strictly local, showing no evidence of systemic spread. After application of I for 6 months, wrinkles were effaced, hair grew, particularly in the axilla, and sweating of the area increased. The effects of II were qualitatively similar though less pronounced, while those o f l I I were weaker still. IV did not improve the skin condition, and tended to suppress hair growth and axillary eccrine sweating. V and VI accentuated the defects of senescence. Microscopic structural improvements in the skin were more impressive than the macroscopic appearances suggested. I, and to a lesser extent II and III, caused thickening of the epidermis, restored regularity in cell size and shape, increased cytoplasmic and nuclear cell content and rendered the nucleoli more distinct. In the dermis, the fibrocytes resumed a plump, stellate form and were better dispersed, while elastic tissue, too, took on a more youthful distribution. In contrast, skin treated with IV was indistinguishable microscopicaUy from control skin, while V and VI provoked atrophy of the epidermis and diminished the cell population of the dermis. [Although in this study the effects of the hormones were strictly localized to the area of application, some critics may feel that more positive evidence of the lack of systemic absorption of testosterone will be necessary before all qualms regarding hormone therapy of the skin can be dismissed.]
BIOCHEMICAL PHARMACOLOGY
1582. Aminopyrine: Poor cow? Banerjee, N. C., Miller, G. E. & Stowe, C. M. (1967). Metabolism and excretion of aminopyrine by cows. Toxic. appl. Pharmac. 10, 596. Banerjee, N. C., Miller, G. E. & Stowe, C. M. (1967). Excretion of aminopyrine and its metabolites into cows' milk. Toxic. appl. PhaJ'mac. 10, 604. The use of aminopyrine (I) in man as an antipyretic and antispasmodic agent has been restricted because of its ability to produce agranulocytosis. No such effects have been observed in domestic animals, in which its use is generally accepted although relatively little is known about its distribution, metabolism and excretion. Banerjee et al. have now pro-
CANCER RESEARCH
435
duced two papers on their studies on aminopyrine in the cow. These indicate that, as in the case of man and the dog, 4-aminoantipyrine (II) and N-acetyl-4-aminoantipyrine (III) are the main metabolites of I in the cow. 4-Hydroxyantipyrine must also be formed, since small amounts of the conjugated form can be detected in both the plasma and urine after infusion of I. Urinary excretion of I, II and III accounts for about 66 ~ of I administered to the cow, 32 o~ /o appearing as the unchanged drug. Corresponding figures for man are 50 and 4 ~ . It is suggested that the main metabolic pathway for I may involve two steps, namely demethylation to II followed by acetylation of the demethylated metabolite to III. During intravenous infusion of doses of I (6.6-42 mg/kg) or II (10-20 mg/kg), all cows showed varying degrees of restlessness. No adverse effect on cattle was apparent with doses of III as high as 66 mg/kg. In the second paper cited above, the mechanism by which I, II and III pass from the systemic circulation into the cow's milk is considered. Experimentally determined ratios of concentrations in milk to those in the plasma ultrafiltrate agreed with theoretical ratios for passive diffusion when I or III were infused, but the experimental values for II were consistently lower than theoretically calculated ratios. Changing the pH of the milk did not affect the anaounts of these compounds passing into it. Thus the appearance of I and III in milk can be explained by diffusion concepts, whereas some other mechanism must be involved in the process by which II gains access to the milk.
CANCER RESEARCH 1583. Can griseofulvin cause liver cancer? Epstein, S. S., Andrea, Joan, Joshi, S. & Mantel, N. (1967). Hepatocarcinogenicity of griseofulvin following parenteral administration to infant mice. Cancer Res. 27, 1900. The subcutaneous injection of griseofulvin (I), suspended in tricaprylin, into infant mice in four doses of 0-5, 0.5, 1.0 and 1.0 mg I on days l, 7, 14 and 21 of life, respectively, induced hepatomas in 44~/o of the 16 male mice which survived for 49 wk. This incidence compared with 18 ~ in mice receiving 0.25 mg instead of 0.5 mg on day 1 and 8 % in the controls injected with solvent only. The hepatomas were solitary or multiple, varying greatly in size and apparently not metastasizing. A high initial mortality followed the injection of doses exceeding 0.25 mg I on day 1. No spontaneous or induced hepatomas occurred in the female mice. The 3-mg total dose which resulted in a high incidence of hepatoma in male mice is equivalent to about 200 mg/kg, while the human oral therapeutic dosage of I is of the order of l0 mg/kg for prolonged periods. The human intake may thus be well above the levels shown in this study to be highly carcinogenic. On the other hand, the test doses were administered parenterally in an oily vehicle to newborn mice, a combination of factors likely to enhance potential hepatocarcinogenicity. Nevertheless, the possibility of a carcinogenic hazard, particularly in children, from the therapeutic use of I cannot be discounted and a need for epidemiological studies following such therapy is strongly indicated. [We have already noted (Cited in F.C.T. 1963, 1, 260) the liver enlargement seen in mice fed griseofulvin in their diet and pointed out that the liver dysfunction caused by the disturbance of porphyrin metabolism by I has apparently led to hepatoma induction in mice. It appears, however, that the significance of hepatoma induction in new-born mice is likely to be as controversial as that of the subcutaneous sarcoma, and it would obviously be unwise to draw hasty conclusions from findings of this nature. Nevertheless, elucidation of this possible hazard of griseofulvin is obviously called for.]
BIOCHEMICAL PHARMACOLOGY
The next stage of the investigation will be to compare the toxicity of various detergents to the living epidermal cell, a piece of research presenting considerable technical difficulty. 1581. Fighting off the wrinkles Papa, C. M. (1967). Effect of topical hormones on aging human skin. J. Soc. cosmet. Chem. 18, 549. The search for the elixir of youth has been one of mankind's favourite occupations, and it is true that a senescent skin, apart from detracting from the appearance, may impair mental and physical well-being in many people. This aspect of growing old lends interest to the study cited above, in which some 200 residents of a home for the aged, almost all of them suffering from obvious skin degeneration, took part. Areas of skin which showed clear-cut alterations attributable to ageing, including those of the face, extensor forearm, back of hand and axilla, were used to test hydrophilic ointments containing 1% testosterone propionate (I), l°'/o progesterone (II), 0.5% pregnenolone acetate (HI), 0.5~o ethinyl oestradiol (IV), 0.59/o triamcinolone acetonide (V) and 0.2% fluocinolone acetonide (VI). Sometimes alcoholic solutions of the same concentration were used. About 0.5 g of the preparation was applied daily, the vehicle without steroid being applied to the corresponding site on the other side of the body as a control. The sex of the subject did not influence the effects of the hormones on the skin. These effects were strictly local, showing no evidence of systemic spread. After application of I for 6 months, wrinkles were effaced, hair grew, particularly in the axilla, and sweating of the area increased. The effects of II were qualitatively similar though less pronounced, while those o f l I I were weaker still. IV did not improve the skin condition, and tended to suppress hair growth and axillary eccrine sweating. V and VI accentuated the defects of senescence. Microscopic structural improvements in the skin were more impressive than the macroscopic appearances suggested. I, and to a lesser extent II and III, caused thickening of the epidermis, restored regularity in cell size and shape, increased cytoplasmic and nuclear cell content and rendered the nucleoli more distinct. In the dermis, the fibrocytes resumed a plump, stellate form and were better dispersed, while elastic tissue, too, took on a more youthful distribution. In contrast, skin treated with IV was indistinguishable microscopicaUy from control skin, while V and VI provoked atrophy of the epidermis and diminished the cell population of the dermis. [Although in this study the effects of the hormones were strictly localized to the area of application, some critics may feel that more positive evidence of the lack of systemic absorption of testosterone will be necessary before all qualms regarding hormone therapy of the skin can be dismissed.]
BIOCHEMICAL PHARMACOLOGY
1582. Aminopyrine: Poor cow? Banerjee, N. C., Miller, G. E. & Stowe, C. M. (1967). Metabolism and excretion of aminopyrine by cows. Toxic. appl. Pharmac. 10, 596. Banerjee, N. C., Miller, G. E. & Stowe, C. M. (1967). Excretion of aminopyrine and its metabolites into cows' milk. Toxic. appl. PhaJ'mac. 10, 604. The use of aminopyrine (I) in man as an antipyretic and antispasmodic agent has been restricted because of its ability to produce agranulocytosis. No such effects have been observed in domestic animals, in which its use is generally accepted although relatively little is known about its distribution, metabolism and excretion. Banerjee et al. have now pro-
CANCER RESEARCH
435
duced two papers on their studies on aminopyrine in the cow. These indicate that, as in the case of man and the dog, 4-aminoantipyrine (II) and N-acetyl-4-aminoantipyrine (III) are the main metabolites of I in the cow. 4-Hydroxyantipyrine must also be formed, since small amounts of the conjugated form can be detected in both the plasma and urine after infusion of I. Urinary excretion of I, II and III accounts for about 66 ~ of I administered to the cow, 32 o~ /o appearing as the unchanged drug. Corresponding figures for man are 50 and 4 ~ . It is suggested that the main metabolic pathway for I may involve two steps, namely demethylation to II followed by acetylation of the demethylated metabolite to III. During intravenous infusion of doses of I (6.6-42 mg/kg) or II (10-20 mg/kg), all cows showed varying degrees of restlessness. No adverse effect on cattle was apparent with doses of III as high as 66 mg/kg. In the second paper cited above, the mechanism by which I, II and III pass from the systemic circulation into the cow's milk is considered. Experimentally determined ratios of concentrations in milk to those in the plasma ultrafiltrate agreed with theoretical ratios for passive diffusion when I or III were infused, but the experimental values for II were consistently lower than theoretically calculated ratios. Changing the pH of the milk did not affect the anaounts of these compounds passing into it. Thus the appearance of I and III in milk can be explained by diffusion concepts, whereas some other mechanism must be involved in the process by which II gains access to the milk.
CANCER RESEARCH 1583. Can griseofulvin cause liver cancer? Epstein, S. S., Andrea, Joan, Joshi, S. & Mantel, N. (1967). Hepatocarcinogenicity of griseofulvin following parenteral administration to infant mice. Cancer Res. 27, 1900. The subcutaneous injection of griseofulvin (I), suspended in tricaprylin, into infant mice in four doses of 0-5, 0.5, 1.0 and 1.0 mg I on days l, 7, 14 and 21 of life, respectively, induced hepatomas in 44~/o of the 16 male mice which survived for 49 wk. This incidence compared with 18 ~ in mice receiving 0.25 mg instead of 0.5 mg on day 1 and 8 % in the controls injected with solvent only. The hepatomas were solitary or multiple, varying greatly in size and apparently not metastasizing. A high initial mortality followed the injection of doses exceeding 0.25 mg I on day 1. No spontaneous or induced hepatomas occurred in the female mice. The 3-mg total dose which resulted in a high incidence of hepatoma in male mice is equivalent to about 200 mg/kg, while the human oral therapeutic dosage of I is of the order of l0 mg/kg for prolonged periods. The human intake may thus be well above the levels shown in this study to be highly carcinogenic. On the other hand, the test doses were administered parenterally in an oily vehicle to newborn mice, a combination of factors likely to enhance potential hepatocarcinogenicity. Nevertheless, the possibility of a carcinogenic hazard, particularly in children, from the therapeutic use of I cannot be discounted and a need for epidemiological studies following such therapy is strongly indicated. [We have already noted (Cited in F.C.T. 1963, 1, 260) the liver enlargement seen in mice fed griseofulvin in their diet and pointed out that the liver dysfunction caused by the disturbance of porphyrin metabolism by I has apparently led to hepatoma induction in mice. It appears, however, that the significance of hepatoma induction in new-born mice is likely to be as controversial as that of the subcutaneous sarcoma, and it would obviously be unwise to draw hasty conclusions from findings of this nature. Nevertheless, elucidation of this possible hazard of griseofulvin is obviously called for.]