Swelling studies of camel and bovine corneal stroma

Abstract

In the present study we investigated the swelling characteristics of fresh camel and bovine cornea in sodium salt solutions. Swelling studies were carried out at 20 minutes, 14 hours, and 46 hours on five fresh camel and 5 five fresh bovine corneas. During the 20-minute hydration of fresh corneal stroma was investigated using sodium chloride (NaCl), sodium bicarbonate (NaHCO(3)), sodium acetate (CH(3)COONa), sodium thiocyanate (NaSCN), and sodium floride (NaF) at 2-minute time intervals. During a 46-hour time period, the hydration study was carried out using NaCl (150, 300 mM) and NaF (150 mM) at random intervals. The 14-hour study was carried out to assess the rehydration of corneal stroma after 6 hours of drying. During the 20-minute swelling studies in the first 2 minutes the rate of hydration in both camel and bovine corneas was high but gradually reduced in the 2-20-minute period. The rates and levels of hydration of camel and bovine cornea were not significantly different from each other in all the strengths of solutions. During the 46-hour swelling studies, the initial rate of hydration (0-2 hours) of camel and bovine stroma, in all solutions was significantly higher (Z = 0.056) compared to hydration during later hours (2-46 hours). Camel stromal hydration (high) in 150 mM NaCl was significantly higher compared to bovine stromal hydration in the same solution during the 10-24, and 24-46-hour time periods. Rehydration in camel stroma was significantly lower than bovine in 150 mM NaF. The 20-minute study showed that there was no selective affinity for particular ions in camel or bovine corneal stroma. Initial swelling in both corneal and bovine stroma is faster and more prominant compared to later swelling. The swelling in camel cornea is more prominant compared to bovine corneal stroma. This could be due to higher negatively charged keratin sulfate-proteoglycans in the stroma. Lower rehydration in camel cornea suggests stronger leaching of proteoglycans from stroma in NaF.

Keywords: camel; proteoglycans; sodium bicarbonate; sodium thiocyanate; swelling.

Figure 1

Change in hydration of camel and bovine corneal stroma in bathing solutions of concentrations 37.5 mM, 70 mM, 150 mM, 300 mM, 600 mM every 2 minutes over a 20-minute time period; A) NaCl pH 7.4; B) NaCl pH 8; C) NaHCO₃; D) NaSCN; E) CH₃COONa.

Figure 2

Change in hydration of camel and bovine corneal stroma in bathing solutions NaCl pH 7.4 (150 mM), NaCl pH 8.4 (300 mM), and NaF (150 mM) over 46 hours; A) Gradual change in hydration at 2-hour intervals over a 46-hour time period; B) Mean change in hydration of camel and bovine corneal stroma at 0–2 hours, 2–10 hours, 10–24 hours, and 24–46 hours; C) Total hydration in camel and bovine corneal stroma at 0–2 hours, 2–10 hours, 10–24 hours, and 24–46 hours.

Figure 3

Change in hydration and rehydration of camel and bovine corneal stroma in bathing solutions NaCl pH 7.4 (150 mM), NaCl pH 8.4 (300 mM), and NaF (150 mM) over 14 hours; A) Gradual change in hydration of camel and bovine corneal stroma at 2-hour intervals over a 14-hour time period; B) Gradual change in rehydration of camel and bovine corneal stroma at 2-hour intervals over a 14-hour time period; C) Mean change in hydration and rehydration of camel and bovine corneal stroma at 0–2 hours, 2–4 hours, and 4–14 hours.