Here's a few tidbits:
Title: Ultrastructural analysis of ruptured tendon from anabolic steroid users.
Author, Editor, Inventor: Evans-Nick-A {a}; Bowrey-David-J; Newman-Geoffrey-R
Author Address: {a} 4 Torrens Dr., Cardiff CF2 6DW, UK
Source: Injury-. Dec., 1998; 29 (10) 769-773.
Publication Year: 1998
Document Type: Article-
ISSN (International Standard Serial Number): 0020-1383
Language: English
Abstract: Tendon rupture has been linked with anabolic steroid abuse on the basis of a small number of published case reports. Although experimental data from animal models suggest steroids alter the biomechanical properties of tendon, ultrastructural evidence to support this theory is lacking. Indeed, microscopic analysis of human tendon from steroid users has not previously been reported. In this study, specimens of ruptured human tendon from four patients were biopsied during surgical repair. Two of the subjects were anabolic steroid users, and two subjects were used as nonsteroid-user controls. Ruptured tendon from both groups was examined using electron microscopy. No differences in collagen fibril ultrastructure were seen. We conclude that anabolic steroids did not induce ultrastructural collagen changes that might predispose to tendon rupture in humans.
Another one:
Title: THE EFFECT OF ANABOLIC STEROIDS ON THE BIOMECHANICAL AND HISTOLOGICAL PROPERTIES OF RAT TENDON.
Author, Editor, Inventor: MILES-J-W {a}; GRANA-W-A; EGLE-D; MIN-K-W; CHITWOOD-J
Author Address: {a} SUITE 310, 711 STANTON L YOUNG BOULEVARD, OKLAHOMA CITY, OKLA 73104
Source: Journal-of-Bone-and-Joint-Surgery-American-Volume. 1992; 74 (3): 411-422.
Publication Year: 1992
Document Type: Article-
ISSN (International Standard Serial Number): 0021-9355
Language: ENGLISH
Abstract: Twenty-four male rats were divided into four groups, with anabolic steroids and exercise as variables. Biomechanical tests and histological evaluations were performed. The results of the biomechanical tests suggested that anabolic steroids product a stiffer tendon, which fails with less elongation. The energy at the time when the tendon failed, the toe-limit elongation, and the elongation at the time of the first failure were all affected significantly. Changes in the force at failure were not statistically significant. No alterations of structure were noted when the specimens were viewed with light microscopy. Alterations of the sizes of the collagen fibrils were noted on electron microscopy. Anabolic steroids are used commonly by athletes to enhance performance in sports activities in which a premium is placed on strength and power. It appears that anabolic steroids have detrimental effects on the muscle-tendon unit in addition to potentially serious systemic side effects. Therefore, athletes who use anabolic steroids place the muscle-tendon unit in double jeopardy of failure. Muscular strength is increased, but the tendon becomes stiffer and absorbs less energy, so it is more likely to fail during certain activities.
Maybe only when using high doses?:
Title: THE EFFECTS OF ANABOLIC STEROIDS ON COLLAGEN SYNTHESIS IN RAT SKELETAL MUSCLE AND TENDON A PRELIMINARY REPORT.
Author, Editor, Inventor: KARPAKKA-J-A {a}; PESOLA-M-K; TAKALA-T-E-S
Author Address: {a} DEP SPORTS MED, DEACONESS INST OULU, SF-90100 OULU, FINLAND
Source: American-Journal-of-Sports-Medicine. 1992; 20 (3): 262-266.
Publication Year: 1992
Document Type: Article-
ISSN (International Standard Serial Number): 0363-5465
Language: ENGLISH
Abstract: We measured the activities of prolyl 4-hydroxylase and galactosylhydroxylysyl glucosyltransferase (both enzymes of collagen biosynthesis) and the concentration of hydroxyproline in male rat soleus muscle and Achilles tendon during anabolic steroid treatment at 1 and 3 weeks. The rats were treated using a therapeutic dosage or a dosage that was five times the therapeutic level. After 1 week, the activity of prolyl 4-hydroxylase decreased significantly (P < 0.01) in both treated groups in the soleus muscle, but the activity of galactosylhydroxylsyl glucosyltransferase decreased significantly (P < 0.05) only in the group given a therapeutic dose. After 3 weeks, the activities were at the control level. In the Achilles tendon, the activity of prolyl 4-hydroxylase and the hydroxyproline concentration decreased significantly (P < 0.05) in the group given high doses at 3 weeks. Anabolic steroid treatment seems to have at least a transitory effect on collagen biosynthesis in male rat muscle and tendon; in tendon this effect is seen only with high doses.