Mitral Regurgitation Occurring During Methysergide (Sansert) Therapy

The case history of a young woman who developed severe mitral regurgitation after four years of methysergide therapy is reported. Replacement of the mitral valve was required. A brief review of the toxic effects of methysergide is given and special reference is made to lesions of the heart valves that have occurred during methysergide therapy.     

Probable inhibition of a bacterial collagenase by serotonin

We have previously demonstrated that intraperitoneal injections in rats of collagenase (from Clostridium histolyticum) are followed by severe lesions. Here we show that the injection of collagenase together with serotonin has no or only small effects. It appears to be partly due to serotonin. Creatinin and sulfate which form an injectable complex with serotonin have no influence on this phenomenon. The part of pH 4,4 of the injected solution is discussed. These facts suggest that serotonin may perhaps lower the collagenolysis and be thus responsible for the fibrogenetic effects of carcinoid tumors, many of these being characterised by their high production of serotonin.     

Inhibition of prolactin secretion by a direct effect of methysergide on the pituitary lactotrophs in the rat

Methysergide administered i.p. caused a dose dependent decrease of serum prolactin levels in rats of both sexes bearing large bilateral electrolytic lesions in the median eminence. This prolactin release inhibiting action of methysergide was prevented by pretreatment of the animals with dopamine receptor blockers pimozide or spiroperidol, which by themselves had no effect on serum prolactin levels. Similar results were observed when the dopamine receptor agonist piribedil was used instead of methysergide. It is concluded that methysergide is capable of inhibiting prolactin secretion by activation of dopamine receptors of the pituitary lactotrophs.     

Effects of p-chlorophenylalanine, α-methyl-p-tyrosine, morphine and chlorpromazine on prostaglandin E1 hyperthermia in the rabbit

Prostaglandin E₁ (PGE₁) has been proposed as the mediator of pyrogen fever. Pyrogen fever has been shown to be enhanced in rabbits pretreated with p-chlorophenylalanine (p-CPA) but depressed in animals pretreated with α-methyl-p-tyrosine (α-MPT). In the present study α-MPT paradoxically enhanced the onset of hyperthermia produced by PGE₁ (5.0 μg) injected into a lateral ventricle. However PGE₁ hyperthermia was not affected by pretreatment with p-CPA, chlorimipramine HCl (5 mg/kg i.v.) or methysergide bimaleate (1 mg/kg i.v.). PGE₁ (0.5 μg) hyperthermia was not altered by either α-MPT or p-CPA pretreatment. These results suggest that if PGE₁ is the mediator of pyrogen fever in the rabbit, the biogenic amines exert their effects prior to the release of PGE₁. Morphine sulphate (10 mg/kg i.v.) and chlorpromazine HCl (5 mg base/kg i.v.) blocked PGE₁ hyperthermia whereas benztropine mesylate (0.2 mg/kg i.v.) was ineffective as an antagonist.     

Anacollagenase by the action of amitriptyline on Clostridium histolyticum collagenase]

Intraperitoneal injection of a mixture of collagenase (300 U) and amitriptyline (Laroxyl*, 3 mg) induce no lesions in contrast with the severe effects of collagenase alone. Also, a complete resistance to intraperitoneal collagenase injection is observed when preceded by 3 intramuscular injections of the same mixture (associated with Freund's incomplete adjuvant). This is due to the development of collagenase antibodies, as demonstrated by nephelometry and immunodiffusion. These facts show that amitriptyline neutralizes the enzymatic properties of collagenase, without alterring its antigenicity. We propose to call this new substance anacollagenase. Such a phenomenon has never been observed with a drug. However we got identical results with other tricyclic depressants (clomipramine, imipramine, doxepine, iprindole). The mechanism of the transformation of collagenase into anacollagenase is not yet explained.     

Proteasic polyseritis: effects of intraperitoneal injections of collagenase, alone or together with the administration of trypsin]

The authors showed previously that the effusions of the experimental polyseritis after intraperitoneal injections of trypsin and elastase, go from peritoneum to the pleural cavities and never from thorax to the peritoneum. The intraperitoneal injections of collagenase or of collagenase and trypsin can also cause polyseritis in the rat; but more often they provoke heavy hemorrhagic lesions of the wall of the abdomen and the diaphragm. Perforations of the diaphragm were observed in 8 rats of 32, with in 6, a intrathoracic hernia of the liver or the stomach. After the intrapleural injection of collagenase or of collagenase and trypsin, hemorrhagic lesions were seen in the thorax, but not in the abdomen. These facts are a new proof for the transdiaphragmatic propagation of the proteasic solutions injected in the peritoneum.     

Insensitivity of some rats to intraperitoneal injections of collagenase and trypsin

In the rat peritoneal injections of collagenase or trypsin give rise to severe lesions. In our experience 20% of the animals remain intact. The frequency of lesions increases with older and heavier subjects. Moreover 25% of the rats who remained free of lesions after a first injection of collagenase resist to a second one. This shows that they are strongly protected against the enzyme. The exact nature and location of this protective mechanism are not known.     

Regulation of human peripheral blood monocyte collagenase by prostaglandins and anti-inflammatory drugs

Macrophages, which produce the collagenolytic enzyme collagenase, are commonly found at sites of connective tissue destruction in chronic inflammatory lesions. Since tissue macrophages are derived from circulating peripheral blood monocytes, we used these less-differentiated, more readily available cells to examine the production and regulation of collagenase. Human monocytes, isolated in large quantities by counterflow centrifugal elutriation, were shown to produce substantial amounts of collagenase when stimulated by concanavalin A (Con A) and to a lesser extent with lipopolysaccharide, while unstimulated monocyte cultures produced negligible collagenase. Collagenase was detected in the culture media within the first 24 hr of culture after activation with peak production at 48 hr. Analysis of the intracellular regulation of collagenase revealed that synthesis of this enzyme required a prostaglandin (PGE₂)-dependent step since indomethacin-inhibited enzyme synthesis was reversed by PGE₂. Additionally, dibutyryladenosine cyclic monophosphate (dBcAMP) restored collagenase synthesis in indomethacinblocked cultures, indicating a PGE₂-dependent generation of cAMP requirement for collagenase production similar to that demonstrated in experimental animals systems. In additional studies, anti-inflammatory drugs which are known to modulate connective tissue destruction were analyzed for their influence on monocyte-derived collagenase. Dexamethasone, colchicine or retinoic acid all inhibited collagenase synthesis by monocytes in a dose-dependent manner although the effect of these drugs on monocyte PGE₂ synthesis differed. Dexamethasone inhibited PGE₂ synthesis, which resulted in the suppression of collagenase. However, PGE₂ production was unaffected by colchicine whereas retinoic acid caused a significant increase in PGE₂ levels. Inhibition of collagenase synthesis by dexamethasone, but not colchicine or retinoic acid, could be reversed by PGE₂ or phospholipase A₂. These findings provide insight into the intracellular events regulating monocyte collagenase synthesis and also implicate monocytes as a target of anti-inflammatory agents which ameliorate connective tissue degradation associated with chronic inflammatory lesions.     

Immunocytochemistry of collagenase expression in transitional cell carcinoma of the bladder

OBJECTIVE: To evaluate the usefulness of collagenase immunocytochemistry as well as its immunohistochemistry in assessing the correlation with prognostic factors in transitional cell carcinoma (TCC) of the urinary bladder. STUDY DESIGN: We investigated the expression of collagenase in catheterized urine and histologic specimens from 38 patients with TCC and 20 cases with benign lesions of the urinary tract. RESULTS: Thirteen (34.2%) and 17 (44.7%) patients with TCC showed positive expression of collagenase on cytologic and histologic specimens, respectively, whereas in no cases with benign lesions was such expression found (P < .01). Invasive and nonpapillary TCC had higher positive rates than noninvasive and papillary TCC. Grade 3 TCC was positive at a higher rate than was grade 2, whereas there were no positive cases with grade 1. Collagenase expression did not correlate significantly with stage. CONCLUSION: Collagenase expression in urinary TCC correlated well with tumor growth pattern, pathologic grade and invasiveness of the carcinoma; all are known to be prognostic factors. The application of collagenase immunostaining to urinary cytology is very useful for assessing prognosis in TCC.     

Additive enhancement of neutrophil collagenase activity by HOCl and cathepsin G.

Using preparations of latent collagenase derived from neutrophil specific granule extracts, the relative effects of cathepsin G and HOCl on activation of neutrophil collagenase were determined using a quantitative collagenase assay. Enhancement of collagenase activity by cathepsin G and physiologically relevant concentrations of HOCl were comparable, but HOCl mediated collagenase activation was reversible in the presence of HOCl scavenger. Collagenase activity in preparations treated with cathepsin G and HOCL simultaneously or sequentially was significantly greater than activity in preparations treated with HOCl or cathepsin G alone. The results indicated additive, yet independent enhancing effects of HOCl and cathepsin G on activity of neutrophil collagenase.     

Environmental pH modulation of collagenase in normal human fibroblast cultures

Normal human skin fibroblast cultures have been used to assess the effects of relatively minor changes in environmental pH on collagenase, a major extracellular gene product. Collagenase accumulation in the culture medium, measured both as enzyme activity and immunoreactive material, was 2- to 10-fold greater at pH 7.6–8.2 than at pH 6.8–7.2. The pH-associated increase in collagenase was parallel by an increase in general protein synthesis. Nevertheless, prototypic lysosomal and cytoplasmic enzymes changed very little under identical culturing conditions. Although substantial intracellular protein degradation occurred at all pH values, the small differences either in general protein degradation or in specific collagenase degradation in the medium were of insufficient magnitude to account for the increased accumulation of collagenase.     

Histopathological features and modulation of type IV collagen expression induced by Pseudomonas aeruginosa lipopolysaccharide (LPS) and porins on mouse skin

BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa) is responsible for serious infections in the immunocompromised host. Many skin lesions induced by P. aeruginosa have been described. Few investigations have been performed on the local action of P. aeruginosa components. OBJECTIVES: To shed light on the "in vivo" activity of lipopolysaccharide (LPS) and porins extracted from P. aeruginosa, by verifying their effects after inoculation in mouse skin through the observation of histological changes and immunohistochemical expression of collagen IV. RESULTS: Both substances were able to induce a similar inflammatory process and a characteristic reversible change in collagen IV distribution. Interestingly, a fibroblast increase was observed at 24 h in the skin treated with porins, while it appeared later in the skin treated with LPS. Besides these changes, porins particularly increased collagen edema, together with disgregation of hypodermal structures. Moreover "in vitro", porins were able to stimulate fibloblasts 3T3 to convert 72 kDa type IV collagenase into the activated 62 kDa form and to release the 92 kDa collagenase. CONCLUSION: LPS and porins, released by gram-negative bacteria during cell growth and lysis, interact with the host at target cells, such as keratinocytes, fibroblasts and immunocompetent cells, thus contributing significantly to the pathogenesis of P aeruginosa skin infections.     

The dominant lethal effects of some ergot alkaloids

The dominant lethal test was carried out in the mouse using the ergot derivatives dihydroergotoxine, ergotamine and methysergide. A significant increase in early fetal deaths was induced by 100 mg/kg of dihydroergotoxine and methysergide. Doses of 25 mg/kg and 50 mg/kg did not induce positive effects. Ergotamine was not effective in doses up to 100 mg/kg. Reduced numbers of implantations were not consistently observed following treatment with the ergot preparations, but some anti-fertility effects were noted. Cyclophosphamide, used as a positive control compound, produced significant effects in doses as low as 25 mg/kg.     

Regulation of guinea pig macrophage collagenase production by dexamethasone and colchicine

Previous studies have demonstrated that exposure of guinea pig macrophages to a primary signal, such as lipopolysaccharide (LPS), stimulates the synthesis of prostaglandin E2 (PGE2) which, in turn, elevates cAMP levels resulting in the production of the enzyme, collagenase. The potential of regulating the biochemical events in this activation sequence was examined with the anti-inflammatory agents dexamethasone and colchicine, which suppress the destructive sequelae in chronic inflammatory lesions associated with the degradation of connective tissue. The addition of dexamethasone with LPS to macrophage cultures resulted in a dose-dependent inhibition of PGE2 and collagenase production, which was reversed by the exogenous addition of phospholipase A2. Collagenase production was also restored in dexamethasone-treated cultures by the addition of products normally produced as a result of phospholipase action, such as arachidonic acid, PGE2 or dibutyryl-cAMP. Since the effect of dexamethasone was thus linked to phospholipase A2 inhibition, mepacrine, a phospholipase inhibitor, was also tested. Mepacrine, like dexamethasone, caused a dose-dependent inhibition of PGE2 and collagenase. In addition to corticosteroid inhibition, colchicine was also found to block collagenase production. However, this anti-inflammatory agent had no effect on PGE2 synthesis. Colchicine was effective only when added at the onset of culture and not 24 h later, implicating a role for microtubules in the transmission of the activation signal rather than enzyme secretion. The failure of lumicolchicine to inhibit collagenase activity provided additional evidence that microtubules are involved in the activation of macrophages. These findings demonstrate that dexamethasone and colchicine act at specific steps in the activation sequence of guinea pig macrophages to regulate collagenase production.     

Purification of proteinase-free collagenase from commercial batches of the enzyme

A method is described for purifying a collagenase fraction from commercial batches of the enzyme, which is free of proteolytic effects. The method, which is based on preparative electrophoresis in discontinuous buffers followed by electroelution, enables the separation and purification of 6 collagenase fractions with a good recovery of the protein (approximately 80%). Proteinase activity was a peculiarity of the low molecular weight components whereas one high MW fraction (C2) had maximal collagenase activity but was free from aspecific proteolytic effects. Only this collagenase should be employed for molecular studies on the collagen composition of the basement membrane.     

Uncoordinate regulation of collagenase,stromelysin, and tissue inhibitor of metalloproteinases genes by prostaglandin E2: Selective enhancement of collagenase gene expression in human dermal fibroblasts in culture

The degradative effects of interleukin-1 (IL-1) on the extracellular matrix of connective tissue are mediated primarily by metalloproteinases and prostaglandins. Clinical observations suggest that these effects can be prevented, to some extent, by the use of non-steroidal anti-inflammatory drugs. We have examined the role of prostaglandin E₂ (PGE₂) in IL-1-induced gene expression by human skin fibroblasts in culture. Incubation of confluent fibroblast cultures with varying concentrations (0.01–1.0 μg/ml) of PGE₂ led to a dose-dependent elevation of collagenase mRNA steady-state levels, the promoter activity, and the secretion of the protein, whereas relatively little effect was observed on stromelysin and TIMP gene expression. Exogenous PGE₂ had no additive or synergistic effect with IL-1 on collagenase gene expression. Furthermore, commonly used non-steroidal anti-inflammatory drugs (indomethacin, acetyl salicylic acid and ibuprofen), at doses which block prostaglandin synthesis in cultured fibroblasts, failed to counteract IL-1-induced collagenase and stromelysin gene expression, nor did they affect TIMP expression. Although the effects of PGE₂ did not potentiate those of IL-1 on collagenase gene expression in vitro, one could speculate that massive production of PGE₂ by connective tissue cells in vivo in response to inflammatory mediators such as IL-1 or tumor necrosis factor-α, could lead to sustained expression of collagenase in connective tissue cells after clearance of the growth factors.     

Equine retained placenta: technique for and tolerance to umbilical artery injections of collagenase

Under laboratory conditions and in clinical experiments, bacterial collagenase has proven to be effective in hydrolyzing placenta and detaching cotyledon from caruncle in the bovine species. Laboratory studies in which placental samples were incubated with collagenase have also demonstrated that collagenase is 3.7 times more effective in hydrolyzing equine placenta than bovine placenta. This led to the hypothesis that collagenase may be a potential treatment for mares with retained placenta. However, that collagenase may hydrolyze the uterine wall and perforate the uterus was a concern. It was the purpose of this study thus to determine any adverse effects of collagenase on the equine uterus and to develop a method for intraplacental injection of collagenase. Three normally expelled intact placentas from Arabian mares, 10 cyclic mixed-breed mares, and 4 mares of various breeds with retained placenta were used. Fluoroscein dye and latex were used to study the placental vasculature and to determine a suitable dose of collagenase; placentas were hydrolyzed by collagenase solution in vitro. Bacterial collagenase solution (40,000 units, 200 ml) was infused into the uterine lumen of each cyclic mare. Uterine biopsies were obtained from the mares before collagenase infusion and again at 16 h and 26 d after infusion. In the mares with retained placenta, each placenta was infused via its umbilical cord vessels with 200,000 units of bacterial collagenase in 1 L of saline. Results showed that none of the uteri from cyclic mares were damaged by collagenase treatment. During a 4-wk period of monitoring (including endoscopy) mares with retained placenta did not show any abnormalities. Retained placentas were expelled in less than 6 h after collagenase treatment. It was concluded that intraplacental injections of collagenase are a safe and potentially effective treatment for retained placenta in mares.     

Effects of chronically elevated intake of sweet solutions on sexual behavior of male rats

Three experiments were conducted on the sexual behavior of gonadally intact and castrated male Sabra rats. Half of the animals drank water during the course of the experiment and half were offered sweet solutions, the assumption being that sweet gustatory stimulation elevates the level of central endogenous opioid peptides in rats. The effects on sexual behavior of the following drugs were explored: the opiate receptor blocker naloxone (5 mg/kg, sc), the serotonin precursor 5-hydroxytryptophan (5-HTP) (20 mg/kg, sc), the serotonin antagonist methysergide (1 mg/kg, sc), and naloxone in combination with methysergide. Naloxone, whether administered alone or in combination with methysergide, impaired sexual performance in castrated male rats, and in gonadally intact rats maintained on sweet solutions. Methysergide elevated sexual behavior in all groups, whereas 5-HTP tended to suppress such behavior. The results support the hypothesis that endogenous opiates play a role in the expression of male sexual behavior in rats. While subtle in intact animals this role may become crucial following the disruption of sex hormone supply. Serotonergic influence on male sexual behavior is inhibitory.