A noninvasive analysis of urinary musculoskeletal collagen metabolism markers from rhesus monkeys subject to chronic hypergravity.

A decrease in load-bearing activity, as experienced during spaceflight or immobilization, affects the musculoskeletal system in animals and humans, resulting in the loss of bone and connective tissue. It has been suggested that hypergravity (HG) can counteract the deleterious effects of microgravity-induced musculoskeletal resorption. However, little consensus information has been collected on the noninvasive measurement of collagen degradation products associated with enhanced load-bearing stress on the skeleton.

Temporal extracellular matrix adaptations in ligament during wound healing and hindlimb unloading.

Previous data from spaceflight studies indicate that injured muscle and bone heal slowly and abnormally compared with ground controls, strongly suggesting that ligaments or tendons may not repair optimally as well. Thus the objective of this study was to investigate the biochemical and molecular gene expression of the collagen extracellular matrix in response to medial collateral ligament (MCL) injury repair in hindlimb unloaded (HLU) rodents. Male rats were assigned to 3- and 7-wk treatment groups with three subgroups each: sham control, ambulatory healing (Amb-healing), and HLU-healing groups.

Systemic administration of IGF-I enhances healing in collagenous extracellular matrices: evaluation of loaded and unloaded ligaments.

Background: Insulin-like growth factor-I (IGF-I) plays a crucial role in wound healing and tissue repair. We tested the hypotheses that systemic administration of IGF-I, or growth hormone (GH), or both (GH+IGF-I) would improve healing in collagenous connective tissue, such as ligament. These hypotheses were examined in rats that were allowed unrestricted activity after injury and in animals that were subjected to hindlimb disuse.

The biphasic response of porcine tendon to recombinant porcine growth hormone.

The purpose of this study was to investigate the effect of recombinant porcine growth hormone (rpGH) administration on the growth and maturational changes of the calcanean tendon in male pigs. Twenty-four orchidectomized crossbred (Duroc X Large White X Landrace) pigs were randomly assigned to 2 months of rpGH-treatment (2mo-rpGH), 3 months of rpGH-treatment (3mo-rpGH), or saline-treated control (Control) groups. Saline or rpGH (10mg/mL given as a constant dose throughout the experiment) was administered twice weekly via 1 mL intramuscular injections.

Extracellular matrix maturation in the left ventricle of normal and diabetic swine.

The main objective of this study is to determine the transmural distribution of extracellular matrix (ECM) collagen and maturation in non-diabetic and diabetic hearts. The Yucatan miniature swine heart ECM was analyzed in eight streptozotocin (STZ) induced diabetic pigs (Diabetic-Swine) and age matched normal control pigs (Nondiabetic-Swine). After 12 weeks of STZ induced diabetes, transmural biopsies were obtained from the left ventricular free wall divided into subendocardial, mid- and subepicardial layers.