Korean J Urol.  2007 Jan;48(1):87-93. 10.4111/kju.2007.48.1.87.

Temporary Opening of the Testis-blood Barrier by Triolein Fat Emulsion

• Lee SD
• Lee W
• Kim HJ

• KMID: 1915028
• DOI: http://doi.org/10.4111/kju.2007.48.1.87

Abstract

PURPOSE: Although the purpose of the blood-testis barrier (BTB) is to protect germ cells from harmful influences, it also impedes the delivery of chemotherapeutic agents to the testis. This study was undertaken to determine whether a triolein emulsion could transiently alter the permeability of the BTB in cats.
MATERIALS AND METHODS
An emulsion of 0.05ml triolein in 20ml of saline or just 20ml of normal saline, as the control, were infused into the testicular arteries in 18 and 15 cats, respectively (embolic and control group). Pre- and post-contrast magnetic resonance images (MRIs) were obtained 30 minutes and 2 hours after embolization. Qualitative and quantitative analyses of the MRIs were performed via the presence and degree of contrast enhancement and the contrast enhancement ratios (CERs), respectively. An electron microscopy (EM) study was subsequently performed, using a lanthanum tracer, to correlate with the MRI results.
RESULTS
Contrast enhancement of the testis was observed in both groups and at both time points, but was more prominent in the embolic group. The CERs in the embolic group were significantly higher than those in the control group (p=0.0001). In each group, the CERs at 2 hours were significantly lower than those at 30 minutes (p=0.006). In the EM study, the entry of lanthanum was markedly increased at 30 mins, but recovered at 2 hours after embolization compared to the control.
CONCLUSIONS
Intra-arterial infusion of triolein emulsion transiently increased the permeability of the BTB. This result may be useful in future studies for a chemotherapy delivery system to the testis.

Keyword

Testis blood barrier; Fats; Emulsions; Cats

MeSH Terms

Animals
Arteries
Blood-Testis Barrier*
Cats
Drug Therapy
Emulsions
Fats
Germ Cells
Infusions, Intra-Arterial
Lanthanum
Magnetic Resonance Imaging
Microscopy, Electron
Permeability
Testis
Triolein*
Emulsions
Fats
Lanthanum
Triolein

Figure

• 

  Fig. 1 Schematic drawing showing the abdominal aorta and its main branches. The right and left internal spermatic arteries originating immediately below the renal arteries. Three ligatures (A, B and C) are indicated. A cannula is inserted retrogradely into aorta between the two lower most ligatures, with the tip is pushed beyond the point of the middle ligature (B). During the perfusion procedure, the three ligatures were tied. Ligature A prevented the fixative from reaching the gastrointestinal tract and thorax; ligature B secured the cannula in the aorta, preventing fixative from reaching the iliac vessels and legs; ligature C secured the cannula in the aorta, preventing displacement. Only the portion of the aorta receiving fixative is a 2-3cm region between ligatures A and B; the left renal artery, two internal spermatic (testicular artery) and lumbar vessels originate from this part of the aorta (from Forssmann et al., 1977).

• 

  Fig. 2 T1-weighted MR images of the testis at 30 minutes (A and B) and 2 hours (C and D) (TR/TE=320/20) in the control group. At 30 minutes, the testes show mild and diffuse contrast enhancement compared to that of muscle (B). In comparison to the image obtained at 30 minutes (B), the testes show decreased contrast enhancement at 2 hours (D).

• 

  Fig. 3 T1-weighted MR images of the testis at 30 minutes (A and B) and 2 hours (C and D) (TR/TE=320/20) in the embolic group. The testes show marked and homogenous enhancement at 30 minutes (B). In comparison to the image obtained at 30 minutes (B), the testes show decreased contrast enhancement at 2 hours (D).

• 

  Fig. 4 Plot of the contrast-enhancement ratio (CER) over time. CERs of the embolic group (solid line) are significantly higher than those of the control group (dotted line) at both 30 minutes and 2 hours (p=0.0001). CERs decrease significantly at 2 hours compared to those at 30 minutes (p=0.0006); however, this decrease showed no significant difference between the control and embolic groups (p=0.1889).

• 

  Fig. 5 Morphological electron microscopy study using a lanthanum electron opaque tracer. Upper (A, B and C) and lower (D, E and F) figures are 4,000 and 25,000 times magnified, respectively. Lanthanum was present in the intercellular spaces throughout the seminiferous cord, which can be seen as a fine, dense line (arrow) at 30 mins after the intra-arterial infusion of the triolein emulsion. Compare to the control, the entry of lanthanum was markedly increased at 30 mins, but recovered at 2 hours after the intra-arterial infusion of the triolein emulsion. Lower figures (D, E and F) demonstrate the circle area of the upper figures (A, B and C).

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