Relaxin (Releasin) Therapy in Diffuse Progressive Scleroderma

Anti‐fibrotic actions of relaxin

“…In diffuse scleroderma, major organ fibrosis occurs along with widespread skin involvement. Early reports indicated that oestrogen priming followed by 20–40 mg doses of porcine relaxin (then known as ‘releasin’) partially resolved skin tightness and Raynaud's symptoms, prompted healing of skin ulcerations that were refractory to corticosteroid treatment and, in limited cases, relieved dysphagia (Casten and Boucek, ; Ismay, ; Evans, ; Rivelis et al ). No improvements were reported in heart, lung or kidney function.…”

Relaxin’s Physiological Roles and Other Diverse Actions

“…It was also postulated that, by inhibiting uterine contractility, relaxin would prevent premature labor, and, by softening the cervix, the hormone would reduce the duration of labor. Clinical efforts with impure porcine relaxin were not sustained beyond the mid-1960s for several reasons, including lack of consistent effectiveness, safety problems (6), and both the time and expense associated with meeting the new and more stringent regulatory requirements of the United States Food and Drug Administration (2, 7). There was nearly no interest in relaxin for about 10 yr. Then, a marked increase in relaxin research occurred between the mid-1970s and 1980s when improved methods for the isolation and characterization of proteins, as well as recombinant DNA technology, made possible rigorous studies of the chemistry and physiology of the hormone.…”

Relaxin

“…Relatively purified preparations in large doses produced no toxic effects in animals (Zarrow & Money, 1948). Never¬ theless, there have been reports of one fatal anaphylactic reaction and one serious but not fatal reaction (Evans, 1959;Wendt & Wolfe, 1959) during clinical trials of the hormone. Never¬ theless, there have been reports of one fatal anaphylactic reaction and one serious but not fatal reaction (Evans, 1959;Wendt & Wolfe, 1959) during clinical trials of the hormone.…”

“…Additional evidence that the hormone affects the rate of cholesterol synthesis, internal configuration of collagen fibres, water content and physical properties of ground substance, and mast cells in this tissue has come from the use of an ingenious sponge biopsy technique by Boucek and his co-workers (Eiden, Sever, . Encouraging results of combined sympathectomy and administration of oestrogen and relaxin in eleven patients with diffuse progressive scleroderma have been described by Evans ( 1959). In the skin of rats, relaxin significantly reduced collagen and hexoseamine content (Sobel, 1953) and produced increased elasticity (Casten & Boucek, 1958).…”