Growth Hormone Effects on Wound Healing in Malnourished Animals: A Histological Study

Abstract

Systemic growth hormone (GH) markedly improves celiotomy wound strength in protein malnourished (PM) animals. This study was undertaken to analyze the effect of GH as a basis for anatomically understanding. Adult female Spraque-Dawley rats were divided into normally nourished controls, PM and GH-treated PM groups. Protein malnutrition was achieved by feeding 5.5% protein restricted chow every other day for eight weeks before surgery. Controls were fed 23.4% protein chow. All animals were fed 23.4% protein chow postoperatively. Rat-GH was injected subcutaneously twice daily (1.0 mg/day) for three days prior to and five days after 5 cm midline celiotomy. Bursting strength of the wound was measured at 3, 6 and 14 days postoperatively. Histologic wound specimens (hematoxylin and eosin) were obtained from each group. Wound strength of malnourished rats was significantly less than that of normal controls at six days after operation (p < 0.001). With administration of growth hormone, the wound strength was significantly improved. Histologically, there was no difference between groups on day 3. On day 6 the normal control group showed a decrease in the early inflammatory cell infiltrate with concurrent development of granulation tissue and a dense proliferation of fibroblasts. The PM wound showed fatty infiltration, a very narrow band of poorly formed granulation tissue and a sparse fibroblastic proliferation. The GH-treated PM group showed a combination of histologic findings. Fatty infiltration, similar to that in malnourished non-treated animals, was still evident but there was also a dense proliferation of capillary channels and fibroblasts comparable to normal animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Transgenic Mice Reveal Novel Activities of Growth Hormone in Wound Repair, Angiogenesis, and Myofibroblast Differentiation

“…The most striking phenotype was the strong increase in granulation tissue formation in female and male transgenic animals. This result is consistent with data obtained by other investigators who found that local or systemic application of GH stimulates granulation tissue formation in wounds of normal and malnourished rats (8,43). However, in the latter and in other studies (9), the increased granulation tissue correlated with an improved biomechanical strength of the wounds.…”

A biodegradable copolymer for the slow release of growth hormone expedites scarring in diabetic rats

“…Many studies have confirmed the positive effects on collagen deposition of GH administered systemically. This effect is observed both in the quantity of collagen fibers deposited and in qualitative factors such as the arrangement and crossing of fibers to form a network 45. In our study, these fibers became reorganized in terms of the different collagen types and their arrangement and alignments in the matrix, only 2 weeks later in the DRP + GH group than in the healthy animals.…”

Growth Hormone (GH) and Wound Healing

“…In addition to the stimulation of granulation tissue formation, GH increases collagen deposition, and facilitates epithelialization [14,15]. This effect of GH has been seen in experimental models of undernourished rats, in which the administration of the hormone made the granulation tissue to grow in previously induced wounds [16]. Similar results have been found in GH-transgenic mice models [17].…”

“…That is, GH therapy not only accelerated the remodeling of the granulation tissue, but also the epithelization, with a more stratified epidermis. Another study showed that the systemic application of GH stimulated the formation of granulation tissue in wounds of malnourished rats [16].…”